First release candidate for v1.9

Changes since v1.7.1

Release notes:

• Statically linked Linux bindists are back again, thanks to @nh2.
  Please try the stack-1.9.0.1-linux-x86_64-static.tar.gz distribution if using Linux, since it will be the default installed version once v1.9.1 is released.
• We will be deleting the Ubuntu, Debian, CentOS, Fedora, and Arch package repos from download.fpcomplete.com soon. These have been deprecated for over a year and have not received new releases, but were left in place for compatibility with older scripts.

Major changes:

• GHCJS support is being downgraded to 'experimental'. A warning notifying the user of the experimental status of GHCJS will be displayed.

Behavior changes:

• ghc-options from stack.yaml are now appended to ghc-options from
  config.yaml, whereas before they would be replaced.
• stack build will now announce when sublibraries of a package are being
  build, in the same way executables, tests, benchmarks and libraries are
  announced
• stack sdist will now announce the destination of the generated tarball,
  regardless of whether or not it passed the sanity checks
• The --upgrade-cabal option to stack setup has been
  deprecated. This feature no longer works with GHC 8.2 and
  later. Furthermore, the reason for this flag originally being
  implemented was drastically lessened once Stack started using the
  snapshot's Cabal library for custom setups. See:
  #4070.
• With the new namespaced template feature, stack templates is no
  longer able to meaningfully display a list of all templates
  available. Instead, the command will download and display a
  help file
  with more information on how to discover templates. See:
  #4039
• Build tools are now handled in a similar way to cabal-install. In
  particular, for legacy build-tools fields, we use a hard-coded
  list of build tools in place of looking up build tool packages in a
  tool map. This both brings Stack's behavior closer into line with
  cabal-install, avoids some bugs, and opens up some possible
  optimizations/laziness. See:
  #4125.
• Mustache templating is not applied to large files (over 50kb) to
  avoid performance degredation. See:
  #4133.
• stack upload signs the package by default, as documented. --no-signature
  turns the signing off.
  #3739
• In case there is a network connectivity issue while trying to
  download a template, stack will check whether that template had
  been downloaded before. In that case, the cached version will be
  used. See #3850.

Other enhancements:

• On Windows before Windows 10, --color=never is the default on terminals that
  can support ANSI color codes in output only by emulation
• On Windows, recognise a 'mintty' (false) terminal as a terminal, by default
• stack build issues a warning when base is explicitly listed in
  extra-deps of stack.yaml
• stack build suggests trying another GHC version should the build
  plan end up requiring unattainable base version.
• A new sub command run has been introduced to build and run a specified executable
  similar to cabal run. If no executable is provided as the first argument, it
  defaults to the first available executable in the project.
• stack build missing dependency suggestions (on failure to construct a valid
  build plan because of missing deps) are now printed with their latest
  cabal file revision hash. See
  #4068.
• Added new --tar-dir option to stack sdist, that allows to copy
  the resulting tarball to the specified directory.
• Introduced the --interleaved-output command line option and
  build.interleaved-output config value which causes multiple concurrent
  builds to dump to stderr at the same time with a packagename> prefix. See
  #3225.
• The default retry strategy has changed to exponential backoff.
  This should help with
  #3510.
• stack new now allows template names of the form username/foo to
  download from a user other than commercialstack on Github, and can be prefixed
  with the service github:, gitlab:, or bitbucket:. #4039
• Switch to githash to include some unmerged bugfixes in gitrev
  Suggestion to add 'allow-newer': true now shows path to user config
  file where this flag should be put into #3685
• stack ghci now asks which main target to load before doing the build,
  rather than after
• Bump to hpack 0.29.0
• With GHC 8.4 and later, Haddock is given the --quickjump flag.
• It is possible to specify the Hackage base URL to upload packages to, instead
  of the default of https://hackage.haskell.org/, by using hackage-base-url
  configuration option.
• When using Nix, if a specific minor version of GHC is not requested, the
  latest minor version in the given major branch will be used automatically.

Bug fixes:

• stack ghci now does not invalidate .o files on repeated runs,
  meaning any modules compiled with -fobject-code will be cached
  between ghci runs. See
  #4038.
• ~/.stack/config.yaml and stack.yaml terminating by newline
• The previous released caused a regression where some stderr from the
  ghc-pkg command showed up in the terminal. This output is now silenced.
• A regression in recompilation checking introduced in v1.7.1 has been fixed.
  See #4001
• stack ghci on a package with internal libraries was erroneously looking
  for a wrong package corresponding to the internal library and failing to
  load any module. This has been fixed now and changes to the code in the
  library and the sublibrary are properly tracked. See
  #3926.
• For packages with internal libraries not depended upon, stack build used
  to fail the build process since the internal library was not built but it
  was tried to be registered. This is now fixed by always building internal
  libraries. See
  #3996.
• --no-nix was not respected under NixOS
• Fix a regression which might use a lot of RAM. See
  #4027.
• Order of commandline arguments does not matter anymore.
  See #3959
• When prompting users about saving their Hackage credentials on upload,
  flush to stdout before waiting for the response so the prompt actually
  displays. Also fixes a similar issue with ghci target selection prompt.
• If cabal is not on PATH, running stack solver now prompts the user
  to run stack install cabal-install
• stack build now succeeds in building packages which contain sublibraries
  which are dependencies of executables, tests or benchmarks but not of the
  main library. See
  #3787.
• Sublibraries are now properly considered for coverage reports when the test
  suite depends on the internal library. Before, stack was erroring when
  trying to generate the coverage report, see
  #4105.
• Sublibraries are now added to the precompiled cache and recovered from there
  when the snapshot gets updated. Previously, updating the snapshot when there
  was a package with a sublibrary in the snapshot resulted in broken builds.
  This is now fixed, see
  #4071.
• [#4114] Stack pretty prints error messages with proper error logging
  level instead of warning now. This also fixes self-executing scripts
  not piping plan construction errors from runhaskell to terminal (issue
  #3942).
• Fix invalid "While building Setup.hs" when Cabal calls fail. See:
  #3934
• stack upload signs the package by default, as documented. --no-signature
  turns the signing off.
  #3739

See https://haskellstack.org for installation and upgrade instructions.

Changes since v1.6.5:

Release notes:

• aarch64 (64-bit ARM) bindists are now available for the first time.
• Statically linked Linux bindists are no longer available, due to difficulty with GHC 8.2.2 on Alpine Linux.
• 32-bit Linux GMP4 bindists for CentOS 6 are no longer available, since GHC 8.2.2 is no longer being built for that platform.

Major changes:

• Upgrade from Cabal 2.0 to Cabal 2.2

Behavior changes:

• stack setup no longer uses different GHC configure options on Linux
  distributions that use GCC with PIE enabled by default. GHC detects
  this itself since ghc-8.0.2, and Stack's attempted workaround for older
  versions caused more problems than it solved.
• stack new no longer initializes a project if the project template contains
  a stack.yaml file.

Other enhancements:

• A new sub command ls has been introduced to stack to view
  local and remote snapshots present in the system. Use stack ls snapshots --help to get more details about it.
• list-dependencies has been deprecated. The functionality has
  to accessed through the new ls dependencies interface. See
  #3669
  for details.
• Specify User-Agent HTTP request header on every HTTP request.
  See #3628 for details.
• stack setup looks for GHC bindists and installations by any OS key
  that is compatible (rather than only checking a single one). This is
  relevant on Linux where different distributions may have different
  combinations of libtinfo 5/6, ncurses 5/6, and gmp 4/5, and will allow
  simpifying the setup-info metadata YAML for future GHC releases.
• The build progress bar reports names of packages currently building.
• stack setup --verbose causes verbose output of GHC configure process.
  See #3716
• Improve the error message when an extra-dep from a path or git reference can't be found
  See #3808
• Nix integration is now disabled on windows even if explicitly enabled,
  since it isn't supported. See
  #3600
• stack build now supports a new flag --keep-tmp-files to retain intermediate
  files and directories for the purpose of debugging.
  It is best used with ghc's equivalent flag,
  i.e. stack build --keep-tmp-files --ghc-options=-keep-tmp-files.
  See #3857
• Improved error messages for snapshot parse exceptions
• stack unpack now supports a --to /target/directory option to
  specify where to unpack the package into
• stack hoogle now supports a new flag --server that launches local
  Hoogle server on port 8080. See
  #2310

Bug fixes:

• The script interpreter's implicit file arguments are now passed before other
  arguments. See #3658.
  In particular, this makes it possible to pass -- +RTS ... -RTS to specify
  RTS arguments used when running the script.
• Don't ignore the template year parameter in config files, and clarify the
  surrounding documentation. See
  #2275.
• Benchmarks used to be run concurrently with other benchmarks
  and build steps. This is non-ideal because CPU usage of other processes
  may interfere with benchmarks. It also prevented benchmark output from
  being displayed by default. This is now fixed. See
  #3663.
• stack ghci now allows loading multiple packages with the same
  module name, as long as they have the same filepath. See
  #3776.
• stack ghci no longer always adds a dependency on base. It is
  now only added when there are no local targets. This allows it to
  be to load code that uses replacements for base. See
  #3589
• stack ghci now uses correct paths for autogen files with
  #3791
• When a package contained sublibraries, stack was always recompiling the
  package. This has been fixed now, no recompilation is being done because of
  sublibraries. See #3899.
• The get-stack.sh install script now matches manual instructions
  when it comes to Debian/Fedora/CentOS install dependencies.
• Compile Cabal-simple with gmp when using Nix.
  See #2944
• stack ghci now replaces the stack process with ghci. This improves
  signal handling behavior. In particular, handling of Ctrl-C. To make
  this possible, the generated files are now left behind after exit.
  The paths are based on hashing file contents, and it's stored in the
  system temporary directory, so this shouldn't result in too much
  garbage. See
  #3821.

Thanks to all our contributors for this release:

• Alexey Kuleshevich
• Andrei Dziahel
• Andrew Cowie
• Daniel Bergey
• David Baynard
• Domen Kožar
• Don Waldhalm
• Emanuel Borsboom
• Geoffrey Noel
• Ivan Kasatenko
• Jan von Loewenstein
• Joshua Simmons
• Kirill Elagin
• Krishnan Parthasarathi
• Luke Murphy
• Matt Spaulding
• Matthias Braun
• Maximilian Tagher
• Michael Sloan
• Michael Snoyman
• Mihai Maruseac
• Mike Pilgrem
• Mitchell Rosen
• Nicolas Mattia
• Niklas Hambüchen
• Oleg Grenrus
• Reuben D'Netto
• Robert J. Macomber
• Sibi Prabakaran
• silky
• Simon Hengel
• Tero Laxström
• tswelsh
• Yuji Yamamoto

Second release candidate for v1.7

Changes since previous release candidate (v1.7.0.1)

Other enhancements:

• stack unpack now supports a --to /target/directory option to
  specify where to unpack the package into
• stack hoogle now supports a new flag --server that launches local
  Hoogle server on port 8080. See
  #2310

Bug fixes:

• When a package contained sublibraries, stack was always recompiling the
  package. This has been fixed now, no recompilation is being done because of
  sublibraries. See #3899.
• The get-stack.sh install script now matches manual instructions
  when it comes to Debian/Fedora/CentOS install dependencies.
• Compile Cabal-simple with gmp when using Nix.
  See #2944
• stack ghci now replaces the stack process with ghci. This improves
  signal handling behavior. In particular, handling of Ctrl-C. To make
  this possible, the generated files are now left behind after exit.
  The paths are based on hashing file contents, and it's stored in the
  system temporary directory, so this shouldn't result in too much
  garbage. See
  #3821.

First release candidate for v1.7.1

Release notes:

• aarch64 (64-bit ARM) bindists are now available for the first time.
• Statically linked Linux bindists are no longer available, due to difficulty with GHC 8.2.2 on Alpine Linux.
• 32-bit Linux GMP4 bindists for CentOS 6 are no longer available, since GHC 8.2.2 is no longer being built for that platform.

Major changes:

• Upgrade from Cabal 2.0 to Cabal 2.2

Behavior changes:

• stack setup no longer uses different GHC configure options on Linux
  distributions that use GCC with PIE enabled by default. GHC detects
  this itself since ghc-8.0.2, and Stack's attempted workaround for older
  versions caused more problems than it solved.

• stack new no longer initializes a project if the project template contains
  a stack.yaml file.

Other enhancements:

• A new sub command ls has been introduced to stack to view
  local and remote snapshots present in the system. Use stack ls snapshots --help to get more details about it.
• list-dependencies has been deprecated. The functionality has
  to accessed through the new ls dependencies interface. See
  #3669
  for details.
• Specify User-Agent HTTP request header on every HTTP request.
  See #3628 for details.
• stack setup looks for GHC bindists and installations by any OS key
  that is compatible (rather than only checking a single one). This is
  relevant on Linux where different distributions may have different
  combinations of libtinfo 5/6, ncurses 5/6, and gmp 4/5, and will allow
  simpifying the setup-info metadata YAML for future GHC releases.
• The build progress bar reports names of packages currently building.
• stack setup --verbose causes verbose output of GHC configure process.
  See #3716
• Improve the error message when an extra-dep from a path or git reference can't be found
  See #3808
• Nix integration is now disabled on windows even if explicitly enabled,
  since it isn't supported. See
  #3600
• stack build now supports a new flag --keep-tmp-files to retain intermediate
  files and directories for the purpose of debugging.
  It is best used with ghc's equivalent flag,
  i.e. stack build --keep-tmp-files --ghc-options=-keep-tmp-files.
  See #3857
• Improved error messages for snapshot parse exceptions

Bug fixes:

• The script interpreter's implicit file arguments are now passed before other
  arguments. See #3658.
  In particular, this makes it possible to pass -- +RTS ... -RTS to specify
  RTS arguments used when running the script.
• Don't ignore the template year parameter in config files, and clarify the
  surrounding documentation. See
  #2275.
• Benchmarks used to be run concurrently with other benchmarks
  and build steps. This is non-ideal because CPU usage of other processes
  may interfere with benchmarks. It also prevented benchmark output from
  being displayed by default. This is now fixed. See
  #3663.
• stack ghci now allows loading multiple packages with the same
  module name, as long as they have the same filepath. See
  #3776.
• stack ghci no longer always adds a dependency on base. It is
  now only added when there are no local targets. This allows it to
  be to load code that uses replacements for base. See
  #3589
• stack ghci now uses correct paths for autogen files with
  #3791

See https://haskellstack.org for installation and upgrade instructions.

Bug fixes:

• 1.6.1 introduced a change that made some precompiled cache files use
  longer paths, sometimes causing builds to fail on windows. This has been
  fixed. See #3649
• Some unnecessary rebuilds when no files were changed are now avoided, by
  having a separate build cache for each component of a package. See
  #3732.
• Correct the behavior of promoting a package from snapshot to local
  package. This would get triggered when version bounds conflicted in
  a snapshot, which could be triggered via Hackage revisions for old
  packages. This also should allow custom snapshots to define
  conflicting versions of packages without issue. See
  Stackage issue #3185.
• When promoting packages from snapshot to local, we were
  occassionally discarding the actual package location content and
  instead defaulting to pulling the package from the index. We now
  correctly retain this information. Note that if you were affected by
  this bug, you will likely need to delete the binary build cache
  associated with the relevant custom snapshot. See
  #3714.
• --no-rerun-tests has been fixed. Previously, after running a test
  we were forgetting to record the result, which meant that all tests
  always ran even if they had already passed before. See
  #3770.
• Includes a patched version of hackage-security which fixes both
  some issues around asynchronous exception handling, and moves from
  directory locking to file locking, making the update mechanism
  resilient against SIGKILL and machine failure. See
  hackage-security #187
  and #3073.

Thanks to all our contributors for this release:

• Arnaud Spiwack
• Artyom
• Artyom Kazak
• Charles Reilly
• Dave Tapley
• Emanuel Borsboom
• Joshua Simmons
• Luke Murphy
• Michael Sloan
• Michael Snoyman
• Nicolas Mattia
• Paolo G. Giarrusso
• Samuel Lelièvre
• Simon Hengel
• Thomas Broadley
• tswelsh

See https://haskellstack.org for installation and upgrade instructions.

Enhancements:

• In addition to supporting .tar.gz and .zip files as remote archives,
  plain .tar files are now accepted too. This will additionally help with
  cases where HTTP servers mistakenly set the transfer encoding to gzip. See
  #3647.
• Links to docs.haskellstack.org ignore Stack version patchlevel.
• Downloading Docker-compatible stack binary ignores Stack version patchlevel.

Bug fixes:

• For versions of Cabal before 1.24, ensure that the dependencies of
  non-buildable components are part of the build plan to work around an old
  Cabal bug. See #3631.
• Run the Cabal file checking in the sdist command more reliably by
  allowing the Cabal library to flatten the
  GenericPackageDescription itself.

See https://haskellstack.org for installation and upgrade instructions.

Note: we are releasing a bit earlier than planned due to #3624. As such, not all the binaries have been built yet, but the commonly used 64-bit binaries of Linux static, macOS, and Windows are available.

In addition, the Windows installer and binary has not been codesigned (we are awaiting validation of a new codesign certificate), and you may see a "Windows Defender SmartScreen prevented an unrecognized app from starting" warning when you try to run them. If so, click on More info, and then click on the Run anyway button that appears.

Changes since v1.5.1

Major changes:

• Complete overhaul of how snapshots are defined, the packages and
  extra-deps fields, and a number of related items. For full
  details, please see
  the writeup on these changes. PR #3249,
  see the PR description for a number of related issues.
• Upgraded to version 2.0 of the Cabal library.

Behavior changes:

• The --install-ghc flag is now on by default. For example, if you
  run stack build in a directory requiring a GHC that you do not
  currently have, Stack will automatically download and install that
  GHC. You can explicitly set install-ghc: false or pass the flag
  --no-install-ghc to regain the previous behavior.
• stack ghci no longer loads modules grouped by package. This is
  always an improvement for plain ghci - it makes loading faster and
  less noisy. For intero, this has the side-effect that it will no
  longer load multiple packages that depend on TH loading relative
  paths. TH relative paths will still work when loading a single
  package into intero. See
  #3309
• Setting GHC options for a package via ghc-options: in your
  stack.yaml will promote it to a local package, providing for more
  consistency with flags and better reproducibility. See:
  #849
• The package-indices setting with Hackage no longer works with the
  00-index.tar.gz tarball, but must use the 01-index.tar.gz file
  to allow revised packages to be found.
• Options passsed via --ghci-options are now passed to the end of the
  invocation of ghci, instead of the middle. This allows using +RTS
  without an accompanying -RTS.
• When auto-detecting --ghc-build, tinfo6 is now preferred over
  standard if both versions of libtinfo are installed
• Addition of stack build --copy-compiler-tool, to allow tools like
  intero to be installed globally for a particular compiler.
  #2643
• Stack will ask before saving hackage credentials to file. This new
  prompt can be avoided by using the save-hackage-creds setting. Please
  see #2159.
• The GHCRTS environment variable will no longer be passed through to
  every program stack runs. Instead, it will only be passed through
  commands like exec, runghc, script, ghci, etc.
  See #3444.
• ghc-options: for specific packages will now come after the options
  specified for all packages / particular sets of packages. See
  #3573.
• The pvp-bounds feature is no longer fully functional, due to some
  issues with the Cabal library's printer. See
  #3550.

Other enhancements:

• The with-hpack configuration option specifies an Hpack executable to use
  instead of the Hpack bundled with Stack. Please
  see #3179.
• It's now possible to skip tests and benchmarks using --skip
  flag
• GitSHA1 is now StaticSHA256 and is implemented using the StaticSize 64 ByteString for improved performance.
  See #3006
• Dependencies via HTTP(S) archives have been generalized to allow
  local file path archives, as well as to support setting a
  cryptographic hash (SHA256) of the contents for better
  reproducibility.
• Allow specifying --git-branch when upgrading
• When running stack upgrade from a file which is different from the
  default executable path (e.g., on POSIX systems,
  ~/.local/bin/stack), it will now additionally copy the new
  executable over the currently running stack executable. If
  permission is denied (such as in /usr/local/bin/stack), the user
  will be prompted to try again using sudo. This is intended to
  assist with the user experience when the PATH environment variable
  has not been properly configured, see
  #3232.
• stack setup for ghcjs will now install alex and happy if
  they are not present. See
  #3109.
• Added stack ghci --only-main flag, to skip loading / importing
  all but main modules. See the ghci documentation page
  for further info.
• Allow GHC's colored output to show through. GHC colors output
  starting with version 8.2.1, for older GHC this does nothing.
  Sometimes GHC's heuristics would work fine even before this change,
  for example in stack ghci, but this override's GHC's heuristics
  when they're broken by our collecting and processing GHC's output.
• Extended the ghc-options field to support $locals, $targets,
  and $everything. See:
  #3329
• Better error message for case that stack ghci file targets are
  combined with invalid package targets. See:
  #3342
• For profiling now uses -fprof-auto -fprof-cafs instead of
  the deprecated -auto-all -caf-all. See:
  #3360
• Better descriptions are now available for stack upgrade --help. See:
  #3070
• When using Nix, nix-shell now depends always on gcc to prevent build errors
  when using the FFI. As ghc depends on gcc anyway, this doesn't increase the
  dependency footprint.
• --cwd DIR can now be passed to stack exec in order to execute the
  program in a different directory. See:
  #3264
• Plan construction will detect if you add an executable-only package
  as a library dependency, resulting in much clearer error
  messages. See:
  #2195.
• Addition of --ghc-options to stack script to pass options directly
  to GHC. See:
  #3454
• Add hpack package.yaml to build Stack itself
• Add ignore-revision-mismatch setting. See:
  #3520.
• Log when each individual test suite finishes. See:
  #3552.
• Avoid spurious rebuilds when using --file-watch by not watching files for
  executable, test and benchmark components that aren't a target. See:
  #3483.
• Stack will now try to detect the width of the running terminal
  (only on POSIX for the moment) and use that to better display
  output messages. Work is ongoing, so some messages will not
  be optimal yet. The terminal width can be overriden with the
  new --terminal-width command-line option (this works even on
  non-POSIX).
• Passing non local packages as targets to stack ghci will now
  cause them to be used as -package args along with package
  hiding.
• Detect when user changed .cabal file instead of package.yaml. This
  was implemented upstream in hpack. See
  #3383.
• Automatically run autoreconf -i as necessary when a configure
  script is missing. See
  #3534
• GHC bindists can now be identified by their SHA256 checksum in addition to
  their SHA1 checksum, allowing for more security in download.
• For filesystem setup-info paths, it's no longer assumed that the
  directory is writable, instead a temp dir is used. See
  #3188.

Bug fixes:

• stack hoogle correctly generates Hoogle databases. See:
  #3362
• stack --docker-help is now clearer about --docker implying
  system-ghc: true, rather than both --docker and --no-docker.
• stack haddock now includes package names for all modules in the
  Haddock index page. See:
  #2886
• Fixed an issue where Stack wouldn't detect missing Docker images
  properly with newer Docker versions.
  #3171
• Previously, cabal files with just test-suite could cause build to fail
  (#2862)
• If an invalid snapshot file has been detected (usually due to
  mismatched hashes), Stack will delete the downloaded file and
  recommend either retrying or filing an issue upstream. See
  #3319.
• Modified the flag parser within Stack to match the behavior of
  Cabal's flag parser, which allows multiple sequential dashes. See
  [#3345](https://gi...

This is the first release candidate for v1.6.1.

Changes since the last v1.6 pre-release (v1.6.0.20171022):

Behavior changes:

• The package-indices setting with Hackage no longer works with the
  00-index.tar.gz tarball, but must use the 01-index.tar.gz file
  to allow revised packages to be found.
• The GHCRTS environment variable will no longer be passed through to
  every program stack runs. Instead, it will only be passed through
  commands like exec, runghc, script, ghci, etc.
  See #3444.
• ghc-options: for specific packages will now come after the options
  specified for all packages / particular sets of packages. See
  #3573.
• The pvp-bounds feature is no longer fully functional, due to some
  issues with the Cabal library's printer. See
  #3550.

Other enhancements:

• Plan construction will detect if you add an executable-only package
  as a library dependency, resulting in much clearer error
  messages. See:
  #2195.
• Addition of --ghc-options to stack script to pass options directly
  to GHC. See:
  #3454
• Add hpack package.yaml to build Stack itself
• Add ignore-revision-mismatch setting. See:
  #3520.
• Log when each individual test suite finishes. See:
  #3552.
• Avoid spurious rebuilds when using --file-watch by not watching files for
  executable, test and benchmark components that aren't a target. See:
  #3483.
• Stack will now try to detect the width of the running terminal
  (only on POSIX for the moment) and use that to better display
  output messages. Work is ongoing, so some messages will not
  be optimal yet. The terminal width can be overriden with the
  new --terminal-width command-line option (this works even on
  non-POSIX).
• Passing non local packages as targets to stack ghci will now
  cause them to be used as -package args along with package
  hiding.
• Detect when user changed .cabal file instead of package.yaml. This
  was implemented upstream in hpack. See
  #3383.
• Automatically run autoreconf -i as necessary when a configure
  script is missing. See
  #3534
• GHC bindists can now be identified by their SHA256 checksum in addition to
  their SHA1 checksum, allowing for more security in download.
• For filesystem setup-info paths, it's no longer assumed that the
  directory is writable, instead a temp dir is used. See
  #3188.

Bug fixes:

• When --pvp-bounds is enabled for sdist or upload, internal
  dependencies could cause errors when uploaded to hackage. This is
  fixed, see #3290
• Fixes a bug where nonexistent hackage versions would cause stack to
  suggest the same package name, without giving version info. See
  #3562
• Fixes a bug that has existed since 1.5.0, where
  stack setup --upgrade-cabal would say that Cabal is already the latest
  version, when it wasn't.
• Ensure that an extra-dep from a local directory is not treated as
  a $locals for GHC options purposes. See
  #3574.
• Building all executables only happens once instead of every
  time. See
  #3229 for
  more info.

This is a pre-release for testing

Changes since v1.5.1

Major changes:

• Complete overhaul of how snapshots are defined, the packages and
  extra-deps fields, and a number of related items. For full
  details, please see
  the writeup on these changes. PR #3249,
  see the PR description for a number of related issues.
• Upgraded to version 2.0 of the Cabal library.

Behavior changes:

• The --install-ghc flag is now on by default. For example, if you
  run stack build in a directory requiring a GHC that you do not
  currently have, Stack will automatically download and install that
  GHC. You can explicitly set install-ghc: false or pass the flag
  --no-install-ghc to regain the previous behavior.
• stack ghci no longer loads modules grouped by package. This is
  always an improvement for plain ghci - it makes loading faster and
  less noisy. For intero, this has the side-effect that it will no
  longer load multiple packages that depend on TH loading relative
  paths. TH relative paths will still work when loading a single
  package into intero. See
  #3309
• Setting GHC options for a package via ghc-options: in your
  stack.yaml will promote it to a local package, providing for more
  consistency with flags and better reproducibility. See:
  #849
• Options passsed via --ghci-options are now passed to the end of the
  invocation of ghci, instead of the middle. This allows using +RTS
  without an accompanying -RTS.
• When auto-detecting --ghc-build, tinfo6 is now preferred over
  standard if both versions of libtinfo are installed
• Addition of stack build --copy-compiler-tool, to allow tools like
  intero to be installed globally for a particular compiler.
  #2643
• Stack will now try to detect the width of the running terminal
  (only on POSIX for the moment) and use that to better display
  output messages. Work is ongoing, so some messages will not
  be optimal yet. The terminal width can be overriden with the
  new --terminal-width command-line option (this works even on
  non-POSIX).
• Stack will ask before saving hackage credentials to file. This new
  prompt can be avoided by using the save-hackage-creds setting. Please
  see #2159.

Other enhancements:

• The with-hpack configuration option specifies an Hpack executable to use
  instead of the Hpack bundled with Stack. Please
  see #3179.
• It's now possible to skip tests and benchmarks using --skip
  flag
• GitSHA1 is now StaticSHA256 and is implemented using the StaticSize 64 ByteString for improved performance.
  See #3006
• Dependencies via HTTP(S) archives have been generalized to allow
  local file path archives, as well as to support setting a
  cryptographic hash (SHA256) of the contents for better
  reproducibility.
• Allow specifying --git-branch when upgrading
• When running stack upgrade from a file which is different from the
  default executable path (e.g., on POSIX systems,
  ~/.local/bin/stack), it will now additionally copy the new
  executable over the currently running stack executable. If
  permission is denied (such as in /usr/local/bin/stack), the user
  will be prompted to try again using sudo. This is intended to
  assist with the user experience when the PATH environment variable
  has not been properly configured, see
  #3232.
• stack setup for ghcjs will now install alex and happy if
  they are not present. See
  #3109.
• --ghc-options and --ghcjs-boot-options now parse their input, so
  multiple arguments can be passed in one option.
  See #3315
• Added stack ghci --only-main flag, to skip loading / importing
  all but main modules. See the ghci documentation page
  for further info.
• Allow GHC's colored output to show through. GHC colors output
  starting with version 8.2.1, for older GHC this does nothing.
  Sometimes GHC's heuristics would work fine even before this change,
  for example in stack ghci, but this override's GHC's heuristics
  when they're broken by our collecting and processing GHC's output.
• Extended the ghc-options field to support $locals, $targets,
  and $everything. See:
  #3329
• Better error message for case that stack ghci file targets are
  combined with invalid package targets. See:
  #3342
• For profiling now uses -fprof-auto -fprof-cafs instead of
  the deprecated -auto-all -caf-all. See:
  #3360
• Better descriptions are now available for stack upgrade --help. See:
  #3070
• When using Nix, nix-shell now depends always on gcc to prevent build errors
  when using the FFI. As ghc depends on gcc anyway, this doesn't increase the
  dependency footprint.
• --cwd DIR can now be passed to stack exec in order to execute the
  program in a different directory. See:
  #3264

Bug fixes:

• stack hoogle correctly generates Hoogle databases. See:
  #3362
• stack --docker-help is now clearer about --docker implying
  system-ghc: true, rather than both --docker and --no-docker.
• stack haddock now includes package names for all modules in the
  Haddock index page. See:
  #2886
• Fixed an issue where Stack wouldn't detect missing Docker images
  properly with newer Docker versions.
  #3171
• Previously, cabal files with just test-suite could cause build to fail
  (#2862)
• If an invalid snapshot file has been detected (usually due to
  mismatched hashes), Stack will delete the downloaded file and
  recommend either retrying or filing an issue upstream. See
  #3319.
• Modified the flag parser within Stack to match the behavior of
  Cabal's flag parser, which allows multiple sequential dashes. See
  #3345
• Now clears the hackage index cache if it is older than the
  downloaded index. Fixes potential issue if stack was interrupted when
  updating index.
  See #3033
• The Stack install script now respects the -d option.
  See #3366.
• stack script can now handle relative paths to source files.
  See #3372.
• Fixes explanation of why a target is needed by the build plan, when the
  target is an extra dependency from the commandline.
  See #3378.
• Previously, if you delete a yaml file from ~/.stack/build-plan, it would
  trust the etag and not re-download. Fixed in this version.
• Invoking stack --docker in parallel now correctly locks the sqlite database.
  See #3400.
• docs.haskellstack.org RTD documentation search is replaced by the mkdocs
  search. Please see
  #3376.
• stack clean now works with nix. See
  #3468.
• stack build --only-dependencies no longer builds local project packages
  that are depended on. See
  #3476.
• Properly handle relative paths stored in the precompiled cache files. See
  #3431.
• In some cases, Cabal does not realize that it needs to reconfigure, and must
  be told to do so automatically. This would manifest as a "shadowed
  dependency" error message. We now force a reconfigure whenever a dependency is
  built, even if the package ID remained the same. See
  #2781.

See https://haskellstack.org for installation and upgrade instructions.

Bug fixes:

• Stack eagerly tries to parse all cabal files related to a
  snapshot. Starting with Stackage Nightly 2017-07-31, snapshots are
  using GHC 8.2.1, and the ghc.cabal file implicitly referenced uses
  the (not yet supported) Cabal 2.0 file format. Future releases of
  Stack will both be less eager about cabal file parsing and support
  Cabal 2.0. This patch simply bypasses the error for invalid parsing.