bpo-34022: Stop forcing of hash-based invalidation with SOURCE_DATE_EPOCH (GH-9607)
Unconditional forcing of ``CHECKED_HASH`` invalidation was introduced in
3.7.0 in bpo-29708. The change is bad, as it unconditionally overrides
*invalidation_mode*, even if it was passed as an explicit argument to
``py_compile.compile()`` or ``compileall``. An environment variable
should *never* override an explicit argument to a library function.
That change leads to multiple test failures if the ``SOURCE_DATE_EPOCH``
environment variable is set.
This changes ``py_compile.compile()`` to only look at
``SOURCE_DATE_EPOCH`` if no explicit *invalidation_mode* was specified.
I also made various relevant tests run with explicit control over the
value of ``SOURCE_DATE_EPOCH``.
While looking at this, I noticed that ``zipimport`` does not work
with hash-based .pycs _at all_, though I left the fixes for
subsequent commits.
(cherry picked from commit a6b3ec5b6d4f6387820fccc570eea08b9615620d)
Co-authored-by: Elvis Pranskevichus <elvis@magic.io>
diff --git a/Doc/library/py_compile.rst b/Doc/library/py_compile.rst
index d720e01..8cb5a4d 100644
--- a/Doc/library/py_compile.rst
+++ b/Doc/library/py_compile.rst
@@ -54,10 +54,10 @@
level of the current interpreter.
*invalidation_mode* should be a member of the :class:`PycInvalidationMode`
- enum and controls how the generated ``.pyc`` files are invalidated at
- runtime. If the :envvar:`SOURCE_DATE_EPOCH` environment variable is set,
- *invalidation_mode* will be forced to
- :attr:`PycInvalidationMode.CHECKED_HASH`.
+ enum and controls how the generated bytecode cache is invalidated at
+ runtime. The default is :attr:`PycInvalidationMode.CHECKED_HASH` if
+ the :envvar:`SOURCE_DATE_EPOCH` environment variable is set, otherwise
+ the default is :attr:`PycInvalidationMode.TIMESTAMP`.
.. versionchanged:: 3.2
Changed default value of *cfile* to be :PEP:`3147`-compliant. Previous
@@ -77,6 +77,11 @@
*invalidation_mode* will be forced to
:attr:`PycInvalidationMode.CHECKED_HASH`.
+ .. versionchanged:: 3.7.2
+ The :envvar:`SOURCE_DATE_EPOCH` environment variable no longer
+ overrides the value of the *invalidation_mode* argument, and determines
+ its default value instead.
+
.. class:: PycInvalidationMode