We do not use curl that much there, setting the HOMEBREW_ON_DEBIAN7 flag
allows to lower the version, so that we can successfully pass the curl
version check below.
Reorder and restructure this file to make it as fast as possible for
e.g. `brew --prefix`. Once we have that, also give `brew shellenv`
short-circuit command execution to make it as fast as possible.
On my machine (with a warm cache) this gets:
```
brew shellenv 0.01s user 0.03s system 100% cpu 0.038 total
```
Compared to:
```
brew shellenv 0.09s user 0.19s system 100% cpu 0.277 total
```
before this commit.
This should help with cases like
https://github.com/Homebrew/homebrew-bundle/issues/751
and is good practise in general.
Also, document the `brew update --preinstall` flag that is being used
here so others can run it manually e.g. as part of CI if needed.
Change the default locale from en_US.UTF-8 to C.UTF-8 on Linux.
The former locale is not included by default in common Docker images,
whereas the latter locale is included by default.
The default locale remains en_US.UTF-8 on macOS.
User may specify which cURL and Git to use via
HOMEBREW_CURL_PATH and HOMEBREW_GIT_PATH.
So, let's use these to determine whether we need to use
their vendored alternatives.
- Concourse CI uses `garden` under the hood for its containers.
- Running the Homebrew Docker container for a Concourse job was failing
with the "can't run as root" error. In the same way as
bc320ad2291f5ec652d8f4bcf3f7b7ff3c9af3bd, this adds `garden` as one of
the allowed providers.
This variable allows a user to configure how often `brew update` runs.
With the previous implementation, however, it was still pretty slow as
it would run some of `brew update` even within the timeout. This feels
related to complaints about Homebrew "feeling slow" since we enabled
this. Address this by:
- making `HOMEBREW_AUTO_UPDATE_SECS` behave more like
`HOMEBREW_NO_AUTO_UPDATE` and entirely skip the invocation of
`brew update` if the relevant tap (homebrew-core or homebrew-cask
depending on command invoked) has been checked in the last
`HOMEBREW_AUTO_UPDATE_SECS`
- Only require/check the update of a single tap rather than every tap
- Increase the default value of `HOMEBREW_AUTO_UPDATE_SECS` from 1m
to 5m to cut people a bit more slack. We're not updating things
often enough for 1m not to feel a bit overkill and 5m feels
appropriate for a Homebrew "session" to only require a single update.
