- Output `brew doctor` and `brew install` messages noting this configuration is (currently) unsupported and encourage use of Rosetta instead
- Output Rosetta 2 usage in `brew config` on ARM (whether in Rosetta 2 or not)
- Check the architecture of (newly installed) dependencies and ensure they are using the correct architecture.
- Don't allow installing macOS Intel Homebrew in macOS ARM Homebrew default prefix (and vice versa
- Actually write out the architecture of dependencies to the tab rather than generating and throwing them away
- Set and document the expected default prefix for macOS Intel Homebrew, macOS ARM Homebrew (`/opt/homebrew`) and Homebrew on Linux
While we're here:
- Don't say Big Sur is a prerelease version but still make it clear we
don't support it (yet).
- Don't reference non-existent IRC channel
When running within an Intel terminal, `uname -m` and friends return Intel-based
values for compatibility. An Intel shell will also prefer to launch Intel slices of
programs unless the program is ARM-only.
It's an open question how Homebrew should manage running in Intel mode. Should it
continue to behave as though the Mac is Intel-based, like it does now? Should it
recognize it's ARM-based? Either way, it's useful for us to be able to tell whether
the Mac is running under Rosetta or whether it's a real Intel Mac.
Darwin 20 adds the CPU family `CPUFAMILY_ARM_VORTEX_TEMPEST`
(aka ARMv8.3-A), which is assigned the identifier of `0x07d34b9f`.
This is relevant for `SystemConfig` in Homebrew.
See also:
https://en.wikipedia.org/wiki/Comparison_of_ARMv8-A_cores
- atomic_write: close file before renaming to prevent error:
'Device or resource busy'
- ensure_writable: preserve executable bit
- new elf? and dynamic? methods
