`update_engine_version.{ps1|sh}` needs to operate on a foreign
repository.
When flutter is run in a git-hook, these environment variables will
override our git calls location and corrupt the install.
fixes: #165390
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Reverts: flutter/flutter#164317
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Initiated by: matanlurey
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Reason for reverting: `bin/cache` does not exist on a fresh checkout,
and `echo bin/cache/...` will fail as a result.
This blocked the google3 roll, but would also break new checkouts of
Flutter, for regular users/contributors.
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Original PR Author: matanlurey
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Reviewed By: {jtmcdole}
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This change reverts the following previous change:
Towards https://github.com/flutter/flutter/issues/164315.
This PR just writes `bin/cache/engine.stamp` identically to how
`bin/internal/engine.version` would otherwise be written, with a caveat
that _if_ `engine.version` is tracked, it is now _copied_ to
`bin/cache/engine.stamp`.
After this lands, I'll send PRs to update tooling that looks for
`engine.version` and give a heads up to the larger team (i.e. Dart HH
bot or whomever we will break by doing this).
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Co-authored-by: auto-submit[bot] <flutter-engprod-team@google.com>
Towards https://github.com/flutter/flutter/issues/164315.
This PR just writes `bin/cache/engine.stamp` identically to how
`bin/internal/engine.version` would otherwise be written, with a caveat
that _if_ `engine.version` is tracked, it is now _copied_ to
`bin/cache/engine.stamp`.
After this lands, I'll send PRs to update tooling that looks for
`engine.version` and give a heads up to the larger team (i.e. Dart HH
bot or whomever we will break by doing this).
Towards https://github.com/flutter/flutter/issues/162201.
**NOTE**: This renames the environment variable to
`FLUTTER_PREBUILT_ENGINE_VERSION`.
---
We occasionally break ourselves, our users, and the Dart up (or is it
down? side-ways) stream repos (i.e. HHH) when we change how the
undocumented
[`update_engine_version.sh`](https://github.com/flutter/flutter/blob/master/bin/internal/update_engine_version.sh)
script, and it's Windows counterpart
[`update_engine_version.ps1`](https://github.com/flutter/flutter/blob/master/bin/internal/update_engine_version.ps1)
work, but have no way of knowing until N days/weeks later when someone
tells us.
For example,
<https://flutter-review.googlesource.com/c/recipes/+/62400>.
This is my attempt to encode "this is what you can guarantee by calling
this script".
It _still_ will be an internal only API that we might rev at any time,
but at least we:
1. Can tell the Dart team "this is tested and how it works"
2. If we want to change it, the tests will keep us from changing it
without informing folks it changed
These tests should (in theory) cover both Linux/MacOS and Windows.
/cc @a-siva
