Race condition during build causing errors with default Python 2.x

[mscdex]

Version

master

Platform

Linux foo 5.4.0-58-generic #64~18.04.1-Ubuntu SMP Wed Dec 9 17:11:11 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

build

What steps will reproduce the bug?

No response

How often does it reproduce? Is there a required condition?

No response

What is the expected behavior?

No response

What do you see instead?

No response

Additional information

There is a race condition occurring when building node where one or more build steps are executed before the python environment is properly set up (e.g. modifying PATH to include a path in out/ containing a symlink to the detected Python 3.x binary). I have Python 2.x as /usr/bin/python but Python 3.6 is also installed (as /usr/bin/python3 and /usr/bin/python3.6).

When the environment isn't set up properly first the build (using make -j 8 for example) fails with:

Traceback (most recent call last):
  File "tools/js2c.py", line 234, in <module>
    main()
  File "tools/js2c.py", line 219, in main
    js_files = utils.SearchFiles(options.directory, 'js')
  File "/home/foo/git/node/tools/utils.py", line 112, in SearchFiles
    list = glob.glob(dir+ '/**/*.' + ext, recursive=True)
TypeError: glob() got an unexpected keyword argument 'recursive'
  touch e6bf3e61ac02f989b2a33f551be26b7ec4082ec4.intermediate
libnode.target.mk:13: recipe for target '/home/foo/git/node/out/Release/obj/gen/node_javascript.cc' failed

At this point if I perform make (without a -j argument), then it works fine and once it gets past the part it was failing on I can abort the build and re-run make -j xxx and everything works fine from then on.

If I had to guess the command it's failing on it might be:

LD_LIBRARY_PATH=/home/foo/git/node/out/Release/lib.host:/home/foo/git/node/out/Release/lib.target:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; cd ../.; mkdir -p /home/foo/git/node/out/Release/obj/gen; python tools/js2c.py --directory lib --target "/home/foo/git/node/out/Release/obj/gen/node_javascript.cc" config.gypi deps/v8/tools/splaytree.mjs deps/v8/tools/codemap.mjs deps/v8/tools/consarray.mjs deps/v8/tools/csvparser.mjs deps/v8/tools/profile.mjs deps/v8/tools/profile_view.mjs deps/v8/tools/logreader.mjs deps/v8/tools/arguments.mjs deps/v8/tools/tickprocessor.mjs deps/v8/tools/sourcemap.mjs deps/v8/tools/tickprocessor-driver.mjs deps/acorn/acorn/dist/acorn.js deps/acorn/acorn-walk/dist/walk.js deps/cjs-module-lexer/lexer.js deps/cjs-module-lexer/dist/lexer.js

[legendecas]

@mscdex As the comment #39465 (comment) suggests, can you check out the content of ./config.mk (which is generated by ./configure), and if out/tool/bin/python presents and where does it linking to? I tested on a Linux system with both python2 and python3 installed and python in PATH is linking to python2, sadly the problem didn't present.