[PATCH v3 1/4] github-actions: run gcc-8 on ubuntu-20.04 image

[Jiang Xin <worldhello.net@gmail.com>]

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

GitHub starts to upgrade its runner image "ubuntu-latest" from version
"ubuntu-20.04" to version "ubuntu-22.04". It will fail to find and
install "gcc-8" package on the new runner image.

Change the runner images from "ubuntu-latest" to "ubuntu-20.04" in order
to run with "gcc-8" as a dependency.

Instead of use the environment "$runs_on_pool" as below:

    case "$runs_on_pool" in
    ubuntu-20.04 | ubuntu-latest)
	;;

we can reuse the os field in the matrix, and use a new environment
"$runs_on_os" as below:

    case "$runs_on_os" in
    ubuntu)
        ;;

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 | 16 ++++++++++++----
 ci/install-dependencies.sh |  6 +++---
 ci/lib.sh                  |  6 +++---
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 592f9193a8..da0d8ab0bf 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -224,6 +224,7 @@ jobs:
         vector:
           - jobname: linux-clang
             cc: clang
+            os: ubuntu
             pool: ubuntu-latest
           - jobname: linux-sha256
             cc: clang
@@ -232,36 +233,43 @@ jobs:
           - jobname: linux-gcc
             cc: gcc
             cc_package: gcc-8
-            pool: ubuntu-latest
+            os: ubuntu
+            pool: ubuntu-20.04
           - jobname: linux-TEST-vars
             cc: gcc
-            os: ubuntu
             cc_package: gcc-8
-            pool: ubuntu-latest
+            os: ubuntu
+            pool: ubuntu-20.04
           - jobname: osx-clang
             cc: clang
+            os: macos
             pool: macos-latest
           - jobname: osx-gcc
             cc: gcc
             cc_package: gcc-9
+            os: macos
             pool: macos-latest
           - jobname: linux-gcc-default
             cc: gcc
+            os: ubuntu
             pool: ubuntu-latest
           - jobname: linux-leaks
             cc: gcc
+            os: ubuntu
             pool: ubuntu-latest
           - jobname: linux-asan
             cc: gcc
+            os: ubuntu
             pool: ubuntu-latest
           - jobname: linux-ubsan
             cc: gcc
+            os: ubuntu
             pool: ubuntu-latest
     env:
       CC: ${{matrix.vector.cc}}
       CC_PACKAGE: ${{matrix.vector.cc_package}}
       jobname: ${{matrix.vector.jobname}}
-      runs_on_pool: ${{matrix.vector.pool}}
+      runs_on_os: ${{matrix.vector.os}}
     runs-on: ${{matrix.vector.pool}}
     steps:
     - uses: actions/checkout@v2
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 107757a1fe..f639263a62 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -11,8 +11,8 @@ UBUNTU_COMMON_PKGS="make libssl-dev libcurl4-openssl-dev libexpat-dev
  tcl tk gettext zlib1g-dev perl-modules liberror-perl libauthen-sasl-perl
  libemail-valid-perl libio-socket-ssl-perl libnet-smtp-ssl-perl"
 
-case "$runs_on_pool" in
-ubuntu-latest)
+case "$runs_on_os" in
+ubuntu)
 	sudo apt-get -q update
 	sudo apt-get -q -y install language-pack-is libsvn-perl apache2 \
 		$UBUNTU_COMMON_PKGS $CC_PACKAGE
@@ -30,7 +30,7 @@ ubuntu-latest)
 		cp git-lfs-$LINUX_GIT_LFS_VERSION/git-lfs .
 	popd
 	;;
-macos-latest)
+macos)
 	export HOMEBREW_NO_AUTO_UPDATE=1 HOMEBREW_NO_INSTALL_CLEANUP=1
 	# Uncomment this if you want to run perf tests:
 	# brew install gnu-time
diff --git a/ci/lib.sh b/ci/lib.sh
index 24d20a5d64..0c0767d354 100755
--- a/ci/lib.sh
+++ b/ci/lib.sh
@@ -225,8 +225,8 @@ export DEFAULT_TEST_TARGET=prove
 export GIT_TEST_CLONE_2GB=true
 export SKIP_DASHED_BUILT_INS=YesPlease
 
-case "$runs_on_pool" in
-ubuntu-latest)
+case "$runs_on_os" in
+ubuntu)
 	if test "$jobname" = "linux-gcc-default"
 	then
 		break
@@ -253,7 +253,7 @@ ubuntu-latest)
 	GIT_LFS_PATH="$HOME/custom/git-lfs"
 	export PATH="$GIT_LFS_PATH:$P4_PATH:$PATH"
 	;;
-macos-latest)
+macos)
 	if [ "$jobname" = osx-gcc ]
 	then
 		MAKEFLAGS="$MAKEFLAGS PYTHON_PATH=$(which python3)"
-- 
2.39.0.rc0