hgdemandimport: disable on Python 3.5
The demand importer functionality isn't working at all on Python 3.5.
I'm not sure what's wrong.
Since it isn't working, let's disable it completely.
```
$ HGRCPATH= hyperfine -w 1 -r 50 -- "~/.pyenv/versions/3.5.9/bin/python ./hg version" \
"HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version"
Benchmark #1: ~/.pyenv/versions/3.5.9/bin/python ./hg version
Time (mean ± σ): 163.7 ms ± 2.2 ms [User: 148.5 ms, System: 15.7 ms]
Range (min … max): 161.0 ms … 170.2 ms 50 runs
Benchmark #2: HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version
Time (mean ± σ): 164.3 ms ± 1.4 ms [User: 148.2 ms, System: 16.6 ms]
Range (min … max): 161.4 ms … 169.8 ms 50 runs
```
Differential Revision: https://phab.mercurial-scm.org/D7953
--- a/hgdemandimport/demandimportpy3.py Sat Jan 18 11:13:01 2020 -0800
+++ b/hgdemandimport/demandimportpy3.py Mon Jan 20 23:42:19 2020 -0800
@@ -36,6 +36,12 @@
_deactivated = False
+# Python 3.5's LazyLoader doesn't work for some reason.
+# https://bugs.python.org/issue26186 is a known issue with extension
+# importing. But it appears to not have a meaningful effect with
+# Mercurial.
+_supported = sys.version_info[0:2] >= (3, 6)
+
class _lazyloaderex(importlib.util.LazyLoader):
"""This is a LazyLoader except it also follows the _deactivated global and
@@ -51,15 +57,9 @@
super().exec_module(module)
-# This is 3.6+ because with Python 3.5 it isn't possible to lazily load
-# extensions. See the discussion in https://bugs.python.org/issue26186 for more.
-if sys.version_info[0:2] >= (3, 6):
- _extensions_loader = _lazyloaderex.factory(
- importlib.machinery.ExtensionFileLoader
- )
-else:
- _extensions_loader = importlib.machinery.ExtensionFileLoader
-
+_extensions_loader = _lazyloaderex.factory(
+ importlib.machinery.ExtensionFileLoader
+)
_bytecode_loader = _lazyloaderex.factory(
importlib.machinery.SourcelessFileLoader
)
@@ -97,6 +97,9 @@
def enable():
+ if not _supported:
+ return
+
sys.path_hooks.insert(0, _makefinder)
--- a/tests/test-demandimport.py Sat Jan 18 11:13:01 2020 -0800
+++ b/tests/test-demandimport.py Mon Jan 20 23:42:19 2020 -0800
@@ -22,6 +22,10 @@
if sys.flags.optimize:
sys.exit(80)
+# The demand importer doesn't work on Python 3.5.
+if sys.version_info[0:2] == (3, 5):
+ sys.exit(80)
+
if ispy3:
from importlib.util import _LazyModule