[PATCH v3 0/4] Fix broken CI on newer github-actions runner image

From: Jiang Xin <zhiyou.jx@alibaba-inc.com>

# Changes since v2

1. Split patch 2/3 of v2 into two patches:

   patch 2/4: ci: show error message of "p4 -V"
   patch 3/4: ci: p4 on Linux has the same version as on macOS

2. In patch 3/4, remove variable "LINUX_P4_VERSION" and use
   a fixed version "21.2" for p4 on both Linux and macOS.

3. For patch 4/4, follow Ævar's suggestion to make the code simpler.

# Range-diff v2..v3

1:  79c851529c ! 1:  1c0d639487 github-actions: run gcc-8 on ubuntu-20.04 image
    @@ Commit message
         In this way, we can change the "ubuntu-latest" runner image to any
         version such as "ubuntu-22.04" to test CI behavior in advance.
     
    +    Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
         Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
     
      ## .github/workflows/main.yml ##
2:  faa5076fe0 ! 2:  fed880b8bd ci: upgrade version of p4 to 21.2
    @@ Metadata
     Author: Jiang Xin <zhiyou.jx@alibaba-inc.com>
     
      ## Commit message ##
    -    ci: upgrade version of p4 to 21.2
    +    ci: show error message of "p4 -V"
     
    -    There would be a segmentation fault when running p4 v16.2 on ubuntu
    -    22.04 which is the latest version of ubuntu runner image for github
    -    actions.
    +    When installing p4 as a dependency, we used to pipe output of "p4 -V" to
    +    validate the installation, but this would hide potential errors of p4.
    +    E.g.: A broken p4 installation fails to run.
     
    -    By checking each version from [1], p4d version 21.1 and above can work
    -    properly on ubuntu 22.04. But version 22.x will break some p4 test
    -    cases. So p4 version 21.x is exactly the version we can use.
    -
    -    In addition to upgrade p4 from version 16.2 to 21.2, also add some
    -    instructions to show errors of command "p4 -V", so we can see why the
    -    command output doesn't match.
    -
    -    [1]: https://cdist2.perforce.com/perforce/
    +    Add some instructions to show errors of command "p4 -V", so we can see
    +    why the command output doesn't match.
     
    +    Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
         Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
     
      ## ci/install-dependencies.sh ##
    @@ ci/install-dependencies.sh: esac
      else
      	echo >&2 "WARNING: perforce wasn't installed, see above for clues why"
      fi
    -
    - ## ci/lib.sh ##
    -@@ ci/lib.sh: ubuntu)
    - 	# were recorded in the Homebrew database upon creating the OS X
    - 	# image.
    - 	# Keep that in mind when you encounter a broken OS X build!
    --	export LINUX_P4_VERSION="16.2"
    -+	export LINUX_P4_VERSION="21.2"
    - 	export LINUX_GIT_LFS_VERSION="1.5.2"
    - 
    - 	P4_PATH="$HOME/custom/p4"
-:  ---------- > 3:  da2f516fc9 ci: p4 on Linux has the same version as on macOS
3:  f080b2fdcd ! 4:  bd1850cc93 ci: install python on ubuntu
    @@ Commit message
         Since the "ubuntu-latest" runner image has a higher version, so its safe
         to use "python2" or "python3" package name.
     
    +    Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
         Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
     
      ## ci/install-dependencies.sh ##
    @@ ci/install-dependencies.sh: case "$runs_on_os" in
     
      ## ci/lib.sh ##
     @@ ci/lib.sh: ubuntu)
    - 	if [ "$jobname" = linux-gcc ]
    + 		break
    + 	fi
    + 
    +-	if [ "$jobname" = linux-gcc ]
    ++	PYTHON_PACKAGE=python2
    ++	if test "$jobname" = linux-gcc
      	then
    - 		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python3"
    +-		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python3"
    +-	else
    +-		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python2"
     +		PYTHON_PACKAGE=python3
    - 	else
    - 		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/python2"
    -+		PYTHON_PACKAGE=python2
      	fi
    ++	MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=/usr/bin/$PYTHON_PACKAGE"
      
      	export GIT_TEST_HTTPD=true
    + 

--

Jiang Xin (4):
  github-actions: run gcc-8 on ubuntu-20.04 image
  ci: show error message of "p4 -V"
  ci: p4 on Linux has the same version as on macOS
  ci: install python on ubuntu

 .github/workflows/main.yml | 16 ++++++++++++----
 ci/install-dependencies.sh | 16 ++++++++--------
 ci/lib.sh                  | 15 +++++++--------
 3 files changed, 27 insertions(+), 20 deletions(-)