[py] BUILD_ROOT environment var to minimise pollution in the source repo

.github/workflows/py.yml

@@ -24,7 +24,7 @@ jobs:
     uses: ./.github/workflows/common.yml
     with:
       workdir: py
-      format-pkgs: python3.11-venv black
+      format-pkgs: python3.11-venv
       build-pkgs: python3.11-venv
       cache-paths: |
         py/venv

py/build.sh

@@ -1,12 +1,18 @@
 #!/usr/bin/env bash
 set -eu
 cd $(dirname $0)
-source py_env.sh
+
+BUILDDIR=${BUILD_ROOT:-$(realpath $(dirname $0))/build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)-venv
+if [ ! -d $BUILDDIR ] ; then
+	python3 -m venv $BUILDDIR
+	$BUILDDIR/bin/pip install pysdl2 pysdl2-dll
+fi
+source $BUILDDIR/bin/activate
 
 cat >rosettaboy-release <<EOD
 #!/usr/bin/env bash
 set -eu
-source "\$(dirname \$0)/py_env.sh"
+source $BUILDDIR/bin/activate
 PYTHONPATH="\$(dirname \$0)" exec python3 -c "from src.main import main ; import sys ; sys.exit(main(sys.argv))" \$*
 EOD
 chmod +x rosettaboy-release

py/build_mypyc.sh

@@ -1,7 +1,14 @@
 #!/usr/bin/env bash
 set -eu
 cd $(dirname $0)
-source py_env.sh
+
+BUILDDIR=${BUILD_ROOT:-$(realpath $(dirname $0))/build}/$(basename $(pwd))-$(echo $(basename $0) | sed 's/build_*\(.*\).sh/\1/')-$(uname)-$(uname -m)-venv
+if [ ! -d $BUILDDIR ] ; then
+	python3 -m venv $BUILDDIR
+	$BUILDDIR/bin/pip install pysdl2 pysdl2-dll 'mypy>=1.0.0'
+fi
+source $BUILDDIR/bin/activate
+
 rm -rf rbmp
 cp -r src rbmp
 sed -i.bak 's/from src./from rbmp./' rbmp/*.py
@@ -11,7 +18,7 @@ mypyc rbmp
 cat >rosettaboy-mypyc <<EOD
 #!/usr/bin/env bash
 set -eu
-source "\$(dirname \$0)/py_env.sh"
+source $BUILDDIR/bin/activate
 PYTHONPATH="\$(dirname \$0)" exec python3 -c "from rbmp.main import main ; import sys ; sys.exit(main(sys.argv))" \$*
 EOD
 chmod +x rosettaboy-mypyc

py/format.sh

@@ -3,7 +3,11 @@ set -eu
 
 cd $(dirname $0)
 
-source py_env.sh
+BUILDDIR=${BUILD_ROOT:-build}/$(basename $(pwd))-$(uname)-$(uname -m)-black
+if [ ! -d $BUILDDIR ] ; then
+	python3 -m venv $BUILDDIR
+	$BUILDDIR/bin/pip install pysdl2 pysdl2-dll 'mypy>=1.0.0' black
+fi
 
-black src/*.py
-mypy src/*.py
+$BUILDDIR/bin/black src/*.py
+$BUILDDIR/bin/mypy src/*.py