dummy commit to trigger Github Actions workflow

[wnienhaus]

Trying to kick-start Github Actions.

[ThomasWaldmann]

Hmm, maybe we could either install all we require (even if it is already there) or not install anything which is there already. Currently we are somehow in the middle of these:

We install, but it is there already:

bison is already the newest version (2:3.0.4.dfsg-1build1).
flex is already the newest version (2.6.4-6).
libffi-dev is already the newest version (3.2.1-8).
libffi-dev set to manually installed.
pkg-config is already the newest version (0.29.1-0ubuntu2).

We do not install, but it is there already(?):

build-essentials

[wnienhaus]

I just tested on a minimal ubuntu 18.04 image (ubuntu:18.04 from docker hub), where no build tools are installed by default, and noticed that the pkg-config package already pulls in everything from build-essential. So I don't know why I remember needing to install build-essentials (maybe this was different on trusty, which I started with, trying to start as close as possible to the Travis build script as possible before).

But what I now also noticed is that a minimal 18.04 needs a bit more installed than what I have in the current workflow step.

It needs:

• git - to clone the repos we're building from
• libffi-dev + pkg-config - for MicroPython
• python3 - for building mpy-cross from MicroPython
• bison + flex - for building binutils-esp32ulp

So our choices are:

• Install nothing, because the Github Actions image already contains all we need
• Install all of the above packages (even though it'll mostly be a no-op)

Now that you pointed me this way, I would actually lean towards the second, because it should (?) make switching to a different build image in the future easier (it's a form of documentation essentially), e.g. when updating to ubuntu-20.04 or similar (currently not possible because binutils doesnt compile). And it would be more resilient to Github potentially changing the build image.

I think I will update the install step to install all we need (i.e. choice 2 above) and if you prefer the other route, I can fix it later. I think I will also throw in build-essentials, just for good measure.

[wnienhaus]

Perhaps also reject this PR, then there's dummy commit cluttering up the history. I will make a new PR for the change to the install step.

[ThomasWaldmann]

as desired...