Fix `entry_points` integration test for PEP 517 (#80357)

This patch pre-builds the sdist via build using the self-eliminating
in-tree build backend and then, feeds the result to a pottentially
outdated pip (below v20) so that it uses the setuptools' native
PEP 517 build backend to build a wheel on install.

1 files changed, 10 insertions, 1 deletions

diff --git a/test/integration/targets/entry_points/runme.sh b/test/integration/targets/entry_points/runme.sh
index cabf153a24..399586f1b0 100755
--- a/test/integration/targets/entry_points/runme.sh
+++ b/test/integration/targets/entry_points/runme.sh
@@ -4,13 +4,22 @@ set -eu -o pipefail
 source virtualenv.sh
 set +x
 unset PYTHONPATH
+export PIP_DISABLE_PIP_VERSION_CHECK=1
 export SETUPTOOLS_USE_DISTUTILS=stdlib
 
 base_dir="$(dirname "$(dirname "$(dirname "$(dirname "${OUTPUT_DIR}")")")")"
 bin_dir="$(dirname "$(command -v pip)")"
 
+
+# NOTE: pip < 20 doesn't support in-tree build backends. This is why, we
+# NOTE: pre-build a compatible sdist that has it self-eliminated. Following
+# NOTE: installs from that artifact will use the setuptools-native backend
+# NOTE: instead, as a compatibility measure for ancient environments.
+pip install 'build ~= 0.10.0'
+python -m build --sdist --outdir="${OUTPUT_DIR}"/dist "${base_dir}"
+
 # deps are already installed, using --no-deps to avoid re-installing them
-pip install "${base_dir}" --disable-pip-version-check --no-deps
+pip install "${OUTPUT_DIR}"/dist/ansible-core-*.tar.gz --no-deps
 # --use-feature=in-tree-build not available on all platforms
 
 for bin in "${bin_dir}/ansible"*; do