mesa-clc: vendor as full-fork recipe (path=source, patches baked)

local/recipes/dev/mesa-clc/source/bin/python-venv.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+set -eu
+
+readonly requirements_file=$1
+shift
+
+venv_dir="$(dirname "$requirements_file")"/.venv
+readonly venv_dir
+readonly venv_req=$venv_dir/requirements.txt
+readonly venv_python_version=$venv_dir/python-version.txt
+
+if [ -d "$venv_dir" ]
+then
+  if [ ! -r "$venv_python_version" ]
+  then
+    echo "Python environment predates Python version checks."
+    echo "It might be invalid and needs to be regenerated."
+    rm -rf "$venv_dir"
+  elif ! cmp --quiet <(python3 --version) "$venv_python_version"
+  then
+    old=$(cat "$venv_python_version")
+    new=$(python3 --version)
+    echo "Python version has changed ($old -> $new)."
+    echo "Python environment needs to be regenerated."
+    unset old new
+    rm -rf "$venv_dir"
+  fi
+fi
+
+if ! [ -r "$venv_dir/bin/activate" ]
+then
+  echo "Creating Python environment..."
+  python3 -m venv "$venv_dir"
+  python3 --version > "$venv_python_version"
+fi
+
+# shellcheck disable=1091
+source "$venv_dir/bin/activate"
+
+if ! cmp --quiet "$requirements_file" "$venv_req"
+then
+  echo "$(realpath --relative-to="$PWD" "$requirements_file") has changed, re-installing..."
+  pip --disable-pip-version-check install --requirement "$requirements_file"
+  cp "$requirements_file" "$venv_req"
+fi
+
+python3 "$@"