Add python-as-wrapper package and use it in asciidoc build.

asciidoc.yaml

@@ -1,7 +1,7 @@
 package:
   name: asciidoc
   version: 10.2.1
-  epoch: 1
+  epoch: 2
   description: "Text based documentation"
   copyright:
     - license: GPL-2.0-or-later
@@ -21,7 +21,8 @@ environment:
       - libxml2-utils
       - libxslt
       - py${{vars.py-version}}-pip
-      - python-${{vars.py-version}}
+      - python-${{vars.py-version}}-base
+      - python3-as-${{vars.py-version}}
       - wolfi-base
 
 pipeline:
@@ -31,10 +32,6 @@ pipeline:
       tag: ${{package.version}}
       expected-commit: 21e33efe96ba9a51d99d1150691dae750afd6ed1
 
-  - uses: patch
-    with:
-      patches: allow-specify-python.yaml
-
   - runs: |
       autoreconf -fi
 
@@ -47,12 +44,8 @@ pipeline:
         --infodir=/usr/share/info
 
   - uses: autoconf/make
-    with:
-      opts: PYTHON=python${{vars.py-version}}
 
   - uses: autoconf/make-install
-    with:
-      opts: PYTHON=python${{vars.py-version}}
 
 update:
   enabled: true

python-as-wrapper.yaml

@@ -0,0 +1,115 @@
+package:
+  name: python-as-wrapper
+  version: 0.1.0
+  epoch: 0
+  description: Shell script wrapper to exec python3.XX
+  copyright:
+    - license: Apache-2.0
+
+# In a "normal" installation of python, 'python3' is a symlink
+# to 'pythonX.Y' where X.Y is Major.Minor (3.13).  In that scenario,
+# if caller invokes 'python3', then when python reads its sys.executable,
+# the executable is 'python3'.
+#
+# That value of sys.executable is "sticky" and finds its way into shbangs that
+# are installed with 'pip install' or other places.
+#
+# In the vast majority of places, we do not want shebang with
+# /usr/bin/python3 because at runtime:
+#  * python3 might be a symlink to another python version
+#  * python3 may not exist at all - with only python3.XX installed.
+#
+# This wrapper will cause the scripts generated by 'python3 -m pip install pkg'
+# to be generated with a shbang of /usr/bin/python3.Y instead of /usr/bin/python3.
+#
+# Note: None of these packages are intended for production use.
+# They are intended to be used to accomodate package build systems
+# That invoke 'python3' or 'python'.
+data:
+  - name: py-versions
+    items:
+      3.10: '310'
+      3.11: '311'
+      3.12: '312'
+      3.13: '313'
+  - name: python-as-names
+    items:
+      python: PYTHON_AS
+      python3: PYTHON3_AS
+
+environment:
+  contents:
+    packages:
+      - busybox
+
+pipeline:
+  - runs: |
+      chmod 755 write-strict write-env
+      chmod 755 test-python3-as-env test-python3-as-wrapper
+
+subpackages:
+  - range: py-versions
+    name: python3-as-${{range.key}}
+    description: provides /usr/bin/python3 that execs python${{range.key}}
+    dependencies:
+      runtime:
+        - python-${{range.key}}-base
+    pipeline:
+      - runs: |
+          ./write-strict "python${{range.key}}" ${{targets.contextdir}}/usr/bin/python3
+    test:
+      environment:
+        contents:
+          packages:
+            - python3-as-test
+      pipeline:
+        - name: validate wrapper 'python3' for ${{range.key}}
+          runs: |
+            python3 /usr/bin/test-python3-as-wrapper \
+              python3 test-python3-as-wrapper ${{range.key}}
+
+  - range: py-versions
+    name: python-as-${{range.key}}
+    description: provides /usr/bin/python that execs python${{range.key}}
+    dependencies:
+      runtime:
+        - python-${{range.key}}-base
+    pipeline:
+      - runs: |
+          ./write-strict "python${{range.key}}" ${{targets.contextdir}}/usr/bin/python
+    test:
+      environment:
+        contents:
+          packages:
+            - python3-as-test
+      pipeline:
+        - name: validate wrapper 'python' for ${{range.key}}
+          runs: |
+            python /usr/bin/test-python3-as-wrapper \
+              python test-python3-as-wrapper ${{range.key}}
+
+  - range: python-as-names
+    name: ${{range.key}}-as-env
+    description: provides /usr/bin/${{range.key}} that execs env var ${{range.value}}
+    pipeline:
+      - runs: |
+          ./write-env "${{range.value}}" ${{targets.contextdir}}/usr/bin/${{range.key}}
+    test:
+      environment:
+        contents:
+          packages:
+            - python3-as-test
+      pipeline:
+        - name: validate wrapper '${{range.key}}'
+          runs: |
+            test-python3-as-env /usr/bin/${{range.key}} ${{range.value}} ${{range.key}}
+
+  - name: python3-as-test
+    description: provides the tests for this package
+    pipeline:
+      - runs: |
+          install -D -m755 "-t${{targets.contextdir}}/usr/bin" test-*
+
+update:
+  enabled: false
+  exclude-reason: No source to watch for the new versions - this is the source.

python-as-wrapper/env-script.tmpl

@@ -0,0 +1,8 @@
+#!/bin/sh
+fail() { echo "FATAL:" "$0" "$@"; exit 9; }
+[ -n "${ENV_NAME}" ] || fail "invoked without ENV_NAME set"
+[ "$ENV_NAME" -ef "$0" ] && fail "invoked with ENV_NAME = $0"
+[ "${ENV_NAME}" != "${0##*/}" ] || fail "invoked with ENV_NAME = basename($0)"
+command -v "$ENV_NAME" >/dev/null ||
+  fail "invoked with ENV_NAME=$ENV_NAME, but $ENV_NAME not found in PATH"
+exec "${ENV_NAME}" "$@"

python-as-wrapper/test-python3-as-env

@@ -0,0 +1,35 @@
+#!/bin/sh
+fail() { echo "FAIL:" "$@"; exit 1; }
+
+wrapper="$1"
+varname="$2"
+wrapped="$3"
+[ -x "$wrapper" ] || fail "$wrapper is not executable file"
+echo "PASS: $wrapper is executable"
+
+if env "$varname=true" "$wrapper"; then
+  echo "PASS: $varname=true exited 0"
+else
+  fail "$wrapper exited $? with $varname=true"
+fi
+
+if env "${varname}=false" "$wrapper"; then
+  fail "$wrapper exited 0 with ${varname}=false"
+else
+  echo "PASS: ${varname}=false exited $?"
+fi
+
+# test that bad values are caught by the wrapper
+# 'wrapped' here is 'python' or 'python3'. We want
+# to check that potential recursion is blocked.
+for val in bogus-prog-name $wrapped /usr/bin/$wrapped; do
+  out=$(env "$varname=$val" "$wrapper" 2>&1)
+  rc=$?
+  case "$rc" in
+    9) echo "PASS: $wrapper exited $rc with ${varname}=$val";;
+    *) echo "output: $out";
+       fail "$wrapper exited $rc with ${varname}=$val";;
+  esac
+done
+
+exit 0

python-as-wrapper/test-python3-as-wrapper

@@ -0,0 +1,12 @@
+#!/usr/bin/python3
+import os, sys
+wrapper = sys.argv[1]
+fname = sys.argv[2]
+majmin = sys.argv[3]
+
+assert f"/usr/bin/python{majmin}" == sys.executable
+assert majmin == "%s.%s" % (sys.version_info.major, sys.version_info.minor)
+assert os.path.basename(sys.argv[0]) == os.path.basename(fname)
+assert len(sys.argv) == 4, f"expected 4 args found {sys.argv}"
+
+print(f"PASS: {wrapper} wrapped {sys.executable} successfully")

python-as-wrapper/write-env

@@ -0,0 +1,13 @@
+#!/bin/sh -e
+input="$1"
+outf="$2"
+d=$(dirname "$0")
+tmpl="$d/env-script.tmpl"
+
+[ -f "$tmpl" ] ||
+    { echo "no 'wrapper-env.tmpl' in dir '$d/'"; exit 1; }
+
+mkdir -p "${outf%/*}"
+sed "s,ENV_NAME,$input,g" "$tmpl" > "$outf"
+
+chmod 755 "$outf"

python-as-wrapper/write-strict

@@ -0,0 +1,11 @@
+#!/bin/sh -e
+input="$1"
+outf="$2"
+mkdir -p "${outf%/*}"
+
+cat >"$outf" <<END
+#!/bin/sh
+exec "$input" "\$@"
+END
+
+chmod 755 "$outf"