proj/portage:master commit in: lib/portage/dep/, man/

commit:     e983b5ea9add519432487733edb6dd468a4bfea1
Author:     Matt Turner <mattst88 <AT> gentoo <DOT> org>
AuthorDate: Sun Aug  2 14:10:57 2026 +0000
Commit:     Matt Turner <mattst88 <AT> gentoo <DOT> org>
CommitDate: Wed Aug  5 21:05:28 2026 +0000
URL:        https://gitweb.gentoo.org/proj/portage.git/commit/?id=e983b5ea

dep: add a PORTAGE_NATIVE_DEP_PARSER kill switch

The native C parser and the pure-Python path are meant to be
indistinguishable.  Provide an escape hatch so that can be verified, and
so a user who does hit a defect in the C parser has a way to keep
working while it is fixed.

Setting PORTAGE_NATIVE_DEP_PARSER=0 in the environment forces the
pure-Python path.  It is read once, when portage.dep is imported, which
happens long before make.conf is parsed -- so it is an environment
variable only, and is documented alongside the other Portage development
variables in emerge(1).

Signed-off-by: Matt Turner <mattst88 <AT> gentoo.org>

 lib/portage/dep/__init__.py |  5 +++++
 man/emerge.1                | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/lib/portage/dep/__init__.py b/lib/portage/dep/__init__.py
index 9dc2fc8ce..48b41849c 100644
--- a/lib/portage/dep/__init__.py
+++ b/lib/portage/dep/__init__.py
@@ -30,6 +30,7 @@ __all__ = [
     "use_reduce",
 ]
 
+import os
 import re
 import warnings
 from functools import lru_cache
@@ -59,6 +60,10 @@ try:
 except ImportError:
     _c_dep_parser = None
 
+# PORTAGE_NATIVE_DEP_PARSER=0 forces the pure-Python path.  See emerge(1).
+if os.environ.get("PORTAGE_NATIVE_DEP_PARSER") == "0":
+    _c_dep_parser = None
+
 if TYPE_CHECKING:
     from _emerge.Package import Package
 

diff --git a/man/emerge.1 b/man/emerge.1
index 00a015586..389caafde 100644
--- a/man/emerge.1
+++ b/man/emerge.1
@@ -1509,6 +1509,17 @@ dependency resolution and fall back to the previous implementation.
 This variable is internal and experimental; it may be removed or changed
 in a future release.
 .TP
+.BR PORTAGE_NATIVE_DEP_PARSER
+If this environment variable is set to \fI0\fR, then Portage will not use
+the native C dependency\-string parser and will fall back to the
+pure\-Python implementation.  Both paths are expected to produce identical
+results; the variable exists to verify that, and to work around a defect in
+the native parser should one be found.  It is read once, when the
+\fBportage.dep\fR module is imported, so it must be set in the environment
+before Portage starts.
+This variable is internal and experimental; it may be removed or changed
+in a future release.
+.TP
 .BR PORTAGE_DO_NOT_EXPORT_PMS_VARS
 If this environment variable is set, then Portage will not export PMS
 variables regardless of the EAPI.  The variables are still available