November 1st 2016 has come and gone so it's time to disable this.
Also, add comments explaining why the things that have been whitelisted
have been (to avoid more being added without good justification).
If you’re using a /usr/local prefix but e.g. /usr/local/homebrew/Cellar
then you’ll miss out on most binary packages for no good reason so warn
people of that.
`Homebrew/>1.0.0 (no git repository) (Macintosh; Intel macOS 10.7.5)...)
reads pretty weirdly in a user agent and I've had complaints that `>`
may be an invalid character in some cases.
For tagged commits produces the output:
- `1.0.1`
For untagged commits with a dirty tree produces the output:
- `1.0.1-19-g23efbc5-dirty`
Performance:
```
git describe --tags --dirty 2> /dev/null
0.07s user 0.01s system 96% cpu 0.086 total
```
This means we can tag any commit without needing to manually remember
to bump the revision every time.
If we have a `brew.sh` which has set
`HOMEBREW_ENABLE_AUTO_UPDATE_MIGRATION` then let's allow an auto-update
migration. That's because it contains the fix below it _before_ the
update happened which means the auto-update won't fail in the same way
as if updating from an old version.
On auto-update `HOMEBREW_LIBRARY` may change location which means that
it won't be found for the actual install command. Look for this having
occurred and then set the new `HOMEBREW_LIBRARY` (and
`HOMEBREW_REPOSITORY`) accordingly.
Not quite a mass replacement as I've used OS X and Mac OS X where
describing specific older versions and added compatibility methods
for things in the DSL.
This seems generally like a good idea given that we're making syntax changes to
formulae & are going to keep doing so for a little while yet. Taps may have moved
over to that syntax, which then causes tap failures if brew isn't up-to-date.
Should fix situations like https://github.com/Homebrew/homebrew-php/issues/3545.
If you're using e.g. a `/usr/local/homebrew` prefix then don't require
the `/usr/local/Cellar` to be manually created to avoid e.g.
`/usr/local/homebrew/Cellar` being used. Let's do all we can to let
people use this `Cellar` location as it means they can put their
repository wherever they like and still use all our bottles.
