Jun 27, 2025 · Jun 28, 2025 · Jun 28, 2025 · Jun 28, 2025 · Jun 29, 2025 · Jun 29, 2025
diff --git a/peps/pep-0796.rst b/peps/pep-0796.rst

 Specifically, we will discuss how such relative paths are understood
 by the Python startup process, including their conversion to absolute
 paths for use by the runtime.
 paths for use by the runtime.
 This is a fundamental building block for virtual environments to
 become more portable.

 There are two main motivations for allowing relative paths in ``pyvenv.cfg``.

 First, it is currently prescribed that the ``home`` value in ``pyvenv.cfg`` be
 an absolute path. The behavior of relative paths is unspecified. While
 an absolute path (`gh-135773`). The behavior of relative paths is unspecified. While
 techniques exist to work around this for every other sub-part of a virtual
 environment, the one remaining part without a tenable solution is how the
 Python runtime itself finds ``PYTHONHOME``. This is because, currently, the
 machines do so either by relying on undocumented interpreter behaviour
 (Bazel, omitting the ``home`` key entirely to trigger an implementation
 dependent fallback to resolving via a symlinked interpreter binary on
 non-Windows systems) or by requiring a post-installation script to be executed
 non-Windows systems, see `gh-135773`) or by requiring a post-installation script to be executed
 after the environment is placed in its target location (venvstacks).

 Specification
 relative paths for ``home`` in ``pyvenv.cfg``.

 Currently, relative paths resolve relative to the process's current working
 directory. BecauseCWDisn't knowable in advance, it makes relative paths today
 effectively impossible.
 directory. Becausethe current working directoryisn't knowable in advance, it
 makes relative paths todayeffectively impossible.

 Instead, the paths should be relative to the location of the ``pyvenv.cfg``
 file. This file is chosen as the anchor point because the tool that creates the
Original file line number	Diff line number	Diff line change
Expand Up		@@ -17,7 +17,7 @@ in a Python virtual environment's :file:`pyvenv.cfg` file.

		Specifically, we will discuss how such relative paths are understood
		by the Python startup process, including their conversion to absolute
		paths for use by the runtime.
		paths for use by the runtime.
		This is a fundamental building block for virtual environments to
		become more portable.

Expand All		@@ -27,7 +27,7 @@ Motivation
		There are two main motivations for allowing relative paths in ``pyvenv.cfg``.
ncoghlan marked this conversation as resolved. OutdatedShow resolvedHide resolved

		First, it is currently prescribed that the ``home`` value in ``pyvenv.cfg`` be
		an absolute path. The behavior of relative paths is unspecified. While
		an absolute path (`gh-135773`). The behavior of relative paths is unspecified. While
		techniques exist to work around this for every other sub-part of a virtual
		environment, the one remaining part without a tenable solution is how the
		Python runtime itself finds ``PYTHONHOME``. This is because, currently, the
Expand DownExpand Up		@@ -83,7 +83,7 @@ Tools that currently look to enable virtual environment portability across
		machines do so either by relying on undocumented interpreter behaviour
		(Bazel, omitting the ``home`` key entirely to trigger an implementation
		dependent fallback to resolving via a symlinked interpreter binary on
		non-Windows systems) or by requiring a post-installation script to be executed
		non-Windows systems, see `gh-135773`) or by requiring a post-installation script to be executed
ncoghlan marked this conversation as resolved. OutdatedShow resolvedHide resolved Copy link Member hugovkSep 30, 2025• edited Loading Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. ~~Lint fix:~~ Alyssa's suggestion below is better.
		after the environment is placed in its target location (venvstacks).
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		Specification
Expand DownExpand Up		@@ -122,8 +122,8 @@ primitives are there, so the only change needed is to define how it resolves
		relative paths for ``home`` in ``pyvenv.cfg``.

		Currently, relative paths resolve relative to the process's current working
		directory. BecauseCWDisn't knowable in advance, it makes relative paths today
		effectively impossible.
		directory. Becausethe current working directoryisn't knowable in advance, it
		makes relative paths todayeffectively impossible.
ncoghlan marked this conversation as resolved. OutdatedShow resolvedHide resolved

		Instead, the paths should be relative to the location of the ``pyvenv.cfg``
		file. This file is chosen as the anchor point because the tool that creates the
Expand Down