Remove attr_rw for CompilerFailure version attribute

This reverts commit 7db9ef9650a44ef8155bf66efd88703e580057b0.
Formula: record full path to non-core formula

If a formula is passed with a relative path, the build process might
try to expand it in the wrong directory, where it doesn't exist.

Fixes #22266.
libvirt 1.1.2

Closes #22262.
Closes #22269.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
ack 2.08

Closes #22214.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Fix various Python import tests.
dart 26639

Closes #22261.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
play devel 2.2.0-RC1

Closes #22270.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
juise 0.5.8

Closes #22251.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
libslax 0.16.18

Closes #22252.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
juise: remove redundant comment
rbenv-gemset 0.4.0

Closes #22254.
fb-client 1.3.0

Closes #22272.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
libftdi: depends on libusb, not libusb-compat

Closes #22258.
Go builds with clang, without cgo module
Sorry, I meant to use ENV.compiler
isl 0.12.1 with more formula cleanups.

* Fix URLs to use new upstream repo and use tag to track stable
  releases.
  - Fix homepage to use freecode site.
  - Fix head URL.
* Now that isl needs to bootstrap before compile.
  - Add :autoconf, :automake, :libtool as build dependencies, and run
    ./autogen.sh before configure.
* Enable verbose build output to help future debugging.
gfortran formula improvement.

* Disable isl and cloog version check to avoid break when they upgrade.
* Enable link-time-optimization (LTO).
python_helper: Comment wording
PythonInstalled: Adding a private_site_packages

that live in the `libexec` dir of a `Cellar`.
PythonInstalled: Allow formulae to set/append PYTHONPATH

Improve robustness of `PYTHONPATH` by first unsetting it (during
`satisfy`) so that the `PythonInstalled` can get the `python.version`
and so forth and then, after that, setting the `PYTHONPATH` to our
`global_site_packages`.
In the `python_helper` we append to the `PYTHONPATH` so if that var has
been set in a formula, it is respected.
Brew audit does no longer complain about setting the
`ENV['PYTHONPATH']`.