* Don't bother reading empty version files
* Implement version file read in pure bash
Is faster with usual sized version files, slower with degenerate cases.
We're going to eliminate the need to mandatorily use `pyenv init --path`.
We can't delete it yet for backward compatibility.
Besides, there's one other use case for it: to enable shims but without
shell integration, e.g. for noninteractive shells.
To be a full-fledged replacement for `pyenv init -` however,
it needs to do rehashing.
Now the setup is to add to both rc and profile:
1) set PYENV_ROOT
(can do it unconditionally -- since if you change it,
you need to update all places anyway since any of them can be run first)
2) Add `pyenv` to PATH if not already there
3) eval "$(pyenv init -)"
Not a breaking change, old setup will continue to work.
Trace logs without `-v` are usually useless due to missing the build part.
So this leaves one less thing for users to worry about
when submitting error reports.
Mentioning `-v` in the issue template should stay for some time
since users report on old versions, too.
This reverts commit 90d0d20508.
After further consideration, we've decided to remove this workaround:
* It only has an effect if the user has added `gnubin` from Homebrew Coreutils to PATH which is an unsupported setup
* It was intended to be applied only to a few select 3.8 and 3.9 versions that officially support Apple Silicon and only fail with Homebrew Coreutils in PATH because they have `config.*` from a too old version of Autoconf that doesn't support the Arm64 arch -- but
* CPython devs [didn't actually fix the problem in 3.10, either, only in 3.11](https://github.com/pyenv/pyenv/pull/2157#issuecomment-968055387), so we'd need to apply it to all 3.10 releases, too
* users started pushing this workaround into other unrelated branches because they were using the above unsupported setup. See https://github.com/pyenv/pyenv/pull/2190#pullrequestreview-835221952 for discussion.
