1740123 - Allow invoking Mach outside of MozillaBuild

Status: RESOLVED FIXED

(Firefox Build System :: Mach Core, enhancement, P3)

Description

[Mitchell Hentges [:mhentges] 🦀]

(this is a discussion ticket about a potential future for MozillaBuild).

The Firefox build depends on Linux-y tools (bash, perl, awk (I believe), etc).
Currently, these are provided in a MozillaBuild package (a little Mozilla-managed MSYS environment) that Windows devs manually install and keep up-to-date.
To work on Firefox, devs must use the MozillaBuild developer shell to interact with Mach.

This ticket proposes that Mach is changed to allow any shell to invoke Mach, so long as Mach is informed where $MOZILLABUILD is.

• For example, from Powershell, you'd run the top-level mach file with Python directly
• This means that Python will no longer (necessarily) run from a MSYS-y context (C:\... instead of /c/...)
• This also would allow flexibility in choosing which Python version to run.

Comment 2

[Mitchell Hentges [:mhentges] 🦀]

Attachment: Bug 1740123: Allow invoking Mach outside of MozillaBuild

Assuming that the MOZILLABUILD environment variable is set, allow
invoking Mach from non-MozillaBuild terminals.

Note that MozillaBuild still needs to be installed, and the
MOZILLABUILD environment variable will have to be set.

For future reference: when I tried setting this up with Windows
Store's Python 3.9, I encountered issues when running binaries installed
via pip: it would fail with abort: failed to load Python DLL python3x.dll.

Comment 3

[Mitchell Hentges [:mhentges] 🦀]

Attachment: Bug 1740123: Move Python version check earlier

Move Python version check as early as possible so that more code can
safely depend on modern behaviour while out-of-date Python version still
get graceful error messages.

Without this change, Python 2 usages fail on importing importlib.util
before the nice warning is printed.

Depends on D133928

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a6eabd95e31d
Move Python version check earlier r=ahal

Comment 5

[Marian-Vasile Laza]

Backed out 2 changesets (Bug 1725895, Bug 1740123) for causing build bustages.
Backout link
Push with failures
Failure Log

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a59de7ebeb2f
Move Python version check earlier r=ahal

Comment 7

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/a59de7ebeb2f

Comment 8

[Mitchell Hentges [:mhentges] 🦀]

Need one more patch to land.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4dfb129adabc
Allow invoking Mach outside of MozillaBuild r=glandium

Comment 10

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/4dfb129adabc

Comment 11

[Mitchell Hentges [:mhentges] 🦀]

For future readers of this bug, the docs for setting this up are available over here. Have fun!