fixup! common/scripts/parse-py-metadata.py: add script to parse pytho…

…n module metadata

Closes: void-linux#53326 [via git-merge-pr]

common/scripts/parse-py-metadata.py

@@ -10,7 +10,7 @@
       - $DESTDIR/$py3_sitelib/*.dist-info/METADATA
       - $DESTDIR/$py3_sitelib/*.egg-info/PKG-INFO
 
-./parse-py-metadata.py -S "$DESTDIR/$py3_sitelib" depends [-s] [-C] -e "extra1 extra2 ..."
+./parse-py-metadata.py -S "$DESTDIR/$py3_sitelib" [-s] [-C] depends -e "extra1 extra2 ..."
     -D "$PKGDESTDIR/rdeps" -V <( xbps-query -R -p provides -s "py3:" )
 
     check that the dependencies of a package match what's listed in the python
@@ -24,21 +24,24 @@
 
 import argparse
 from pathlib import Path
+from sys import stderr
+from typing import TYPE_CHECKING
 
-from packaging.metadata import Metadata
-from packaging.requirements import Requirement
-from packaging.utils import canonicalize_name
+if TYPE_CHECKING:
+    from packaging.metadata import Metadata
+    from packaging.requirements import Requirement
+    from packaging.utils import canonicalize_name
 
 
 def msg_err(msg: str, *, nocolor: bool = False, strict: bool = False):
     if nocolor:
         print(msg)
     else:
         color = "31" if strict else "33"
-        print(f"\033[1m\033[{color}m{msg}\033[m")
+        print(f"\033[1m\033[{color}m{msg}\033[m", file=stderr)
 
 
-def vpkgname(val: str | Requirement, *, version: str | None = None) -> str:
+def vpkgname(val: "str | Requirement", *, version: str | None = None) -> str:
     sfx = ""
     if version is not None:
         sfx = f"-{version}"
@@ -66,7 +69,7 @@ def getpkgdepname(pkgdep: str) -> str:
         return pkgdep.rpartition("-")[0]
 
 
-def match_markers(req: Requirement, extras: set[str]) -> bool:
+def match_markers(req: "Requirement", extras: set[str]) -> bool:
     # unconditional requirement
     if req.marker is None:
         return True
@@ -172,6 +175,8 @@ def parse_depends(args):
     parser = argparse.ArgumentParser()
     parser.add_argument("-S", dest="sitepkgs", type=Path)
     parser.add_argument("-v", dest="pkgver")
+    parser.add_argument("-s", dest="strict", action="store_true")
+    parser.add_argument("-C", dest="nocolor", action="store_true")
     subparsers = parser.add_subparsers()
 
     prov_parser = subparsers.add_parser("provides")
@@ -181,9 +186,18 @@ def parse_depends(args):
     deps_parser.add_argument("-e", dest="extras", default="")
     deps_parser.add_argument("-V", dest="vpkgs", type=Path)
     deps_parser.add_argument("-D", dest="rdeps", type=Path)
-    deps_parser.add_argument("-s", dest="strict", action="store_true")
-    deps_parser.add_argument("-C", dest="nocolor", action="store_true")
     deps_parser.set_defaults(func=parse_depends)
 
     args = parser.parse_args()
+
+    try:
+        from packaging.metadata import Metadata
+        from packaging.requirements import Requirement
+        from packaging.utils import canonicalize_name
+    except ImportError:
+        msg_err(f"=> WARNING: {args.pkgver}: missing packaging module!\n"
+                f"=> WARNING: {args.pkgver}: please add python3-packaging-bootstrap to hostmakedepends to run this check",
+                nocolor=args.nocolor)
+        exit(0)
+
     args.func(args)