Upgrade flake8/pyflakes for Py3 compatibility
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Do not raise StopIteration: PEP 479
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This fixes `test-tidy` Py3 compatibility, as [PEP 479](https://www.python.org/dev/peps/pep-0479/) says `return` must be used to stop iteration inside generator instead of `raise StopIteration`.
This introduces subtle behavior change where `FileList()` constructor now won't implicitly stop the caller generator when the list is empty. `wpt_lint.py` is modified to explicitly stop when empty, to match the change.
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Fix Py3 environment setting failures
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`python3 mach build -d` now proceeds to actual build. Since Gecko landed full Python 3 support, updating mozjs should allow us to drop Python 2 to build Servo. (I still see failures on other commands e.g. `test-tidy`.)
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Show the real commit hash for `./servo --version`, not the bundle hash
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Show the real commit hash of the build when run on a bundle commit, rather than showing the bundle's hash.
It gets the real commit hash by extracting it from the bundle commit message, which has the form `Shallow version of commit {sha1}`, where `{sha1}` is the real commit hash.
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- [x] `./mach build -d` does not report any errors (edits Python code, no Rust changes)
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#26386 (GitHub issue number if applicable)
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Support building on Void Linux
Adds support for building on Void Linux.
Since this distribution uses LibreSSL, currently it's not possible to link against it. So this adds `openssl-src` feature to corresponding crates in order to activate `openssl/vendored`.
Automatic activation of this feature on Void is also included in build system.
*Note*: #26117 will activate `openssl/vendored` by default. If that's the case, I will just keep the package names in `./mach`.
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- [X] These changes fix#26114
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Replace glutin by winit + surfman 0.2
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This PR updates surfman to 0.2, and replaces glutin with winit+surfman.
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Report error when vcvarsall fails
In trying to get my Windows cross build working on my desktop, I ended up spending a lot of time trying to replicate a failure within servo's build system that ultimately turned out to be vcvarsall silently failing (I was missing a trailing slash in my `VSINSTALLDIR` env var, which vcvarsall does not handle well at all)
We should report an error when this happens.
r? @jdm
