gitlab-ci: download gfortran as part of the CI job

.gitlab/ci/install_gfortran.sh

+#!/bin/sh
+
+set -e
+
+readonly version="9.2"
+readonly patch="0"
+# From https://downloads.sourceforge.net/project/hpc/hpc/g95/gfortran-$version-bin.tar.gz
+readonly tarball="gfortran-$version-bin.tar.gz"
+readonly sha256sum="89f549739d4713a21781c7e478c3627ab9ad4133629ffab1e1de65c0cbc3329b"
+
+cd .gitlab
+
+echo "$sha256sum  $tarball" > gfortran.sha256sum
+curl -OL "https://www.paraview.org/files/dependencies/$tarball"
+shasum -a 256 --check gfortran.sha256sum
+mkdir -p gfortran
+# The tarball is hard-coded to live in `usr/local`. We need to make it
+# minimally relocatable.
+tar --strip-components 2 -C gfortran -xzf "$tarball"
+
+# Fixup the references so that the toolchain is usable from the CI directory.
+install_name_tool -change /usr/local/lib/libmpc.3.dylib @loader_path/../../../../lib/libmpc.3.dylib "gfortran/libexec/gcc/x86_64-apple-darwin19/$version.$patch/f951"
+install_name_tool -change /usr/local/lib/libmpfr.4.dylib @loader_path/../../../../lib/libmpfr.4.dylib "gfortran/libexec/gcc/x86_64-apple-darwin19/$version.$patch/f951"
+install_name_tool -change /usr/local/lib/libgmp.10.dylib @loader_path/../../../../lib/libgmp.10.dylib "gfortran/libexec/gcc/x86_64-apple-darwin19/$version.$patch/f951"
+install_name_tool -change /usr/local/lib/libmpfr.4.dylib @loader_path/libmpfr.4.dylib gfortran/lib/libmpc.3.dylib
+install_name_tool -change /usr/local/lib/libgmp.10.dylib @loader_path/libgmp.10.dylib gfortran/lib/libmpc.3.dylib
+install_name_tool -change /usr/local/lib/libgmp.10.dylib @loader_path/libgmp.10.dylib gfortran/lib/libmpfr.4.dylib

.gitlab/os-macos.yml

@@ -44,7 +44,8 @@
 .before_script_macos: &before_script_macos
     - .gitlab/ci/cmake.sh
     - .gitlab/ci/ninja.sh
-    - export PATH=$PWD/.gitlab:$PWD/.gitlab/cmake/bin:$PATH
+    - .gitlab/ci/gfortran.sh
+    - export PATH=$PWD/.gitlab:$PWD/.gitlab/cmake/bin:$PWD/.gitlab/gfortran/bin;$PATH
     - cmake --version
     - ninja --version
     # Download Qt