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/compileall.rst b/Doc/library/compileall.rst
index 7b3963d..5151f3a 100644
--- a/Doc/library/compileall.rst
+++ b/Doc/library/compileall.rst
@@ -85,13 +85,16 @@
.. cmdoption:: --invalidation-mode [timestamp|checked-hash|unchecked-hash]
- Control how the generated pycs will be invalidated at runtime. The default
- setting, ``timestamp``, means that ``.pyc`` files with the source timestamp
+ Control how the generated byte-code files are invalidated at runtime.
+ The ``timestamp`` value, means that ``.pyc`` files with the source timestamp
and size embedded will be generated. The ``checked-hash`` and
``unchecked-hash`` values cause hash-based pycs to be generated. Hash-based
pycs embed a hash of the source file contents rather than a timestamp. See
- :ref:`pyc-invalidation` for more information on how Python validates bytecode
- cache files at runtime.
+ :ref:`pyc-invalidation` for more information on how Python validates
+ bytecode cache files at runtime.
+ The default is ``timestamp`` if the :envvar:`SOURCE_DATE_EPOCH` environment
+ variable is not set, and ``checked-hash`` if the ``SOURCE_DATE_EPOCH``
+ environment variable is set.
.. versionchanged:: 3.2
Added the ``-i``, ``-b`` and ``-h`` options.