Delegate to `rbenv-shims` instead of `rbenv shims` and therefore skip
going through the main `rbenv` executable again that would set up a lot
of the environment that was already set.
Running any shim (and thus `rbenv-exec`) would always execute
`rbenv-version-name` twice: once in `rbenv-exec` and another time in
`rbenv-which`, even though RBENV_VERSION variable would have already
been populated at this point.
Now RBENV_VERSION is respected within `rbenv-which`.
It's slow and not necessary since we expect `$0` to already be expanded.
In tests this change forces us to deal with some relative paths, but
it's not a big deal. The `rbenv init -` output in the most common case
will be the same as before:
source '/home/myuser/.rbenv/libexec/../completions/rbenv.bash'
On systems that support both C compiling and dynamic loading, we can
speed up `realpath()` (where most time in rbenv is spent) by replacing
it with a dynamically loaded bash builtin.
When `make -C src` is called in the project's root,
`libexec/rbenv-realpath.dylib` will be created. If it exists, rbenv will
attempt to load it as a builtin command. If it fails, execution will
fall back to the old `realpath()` shell function.
With e.g. /usr/local/bin/.python-version owned by some user, `pyenv
local foo` would fail, if the user has no permissions for
`/usr/local/bin`, but only the `.python-version` file.
When created on Windows, .rbenv-version or .ruby-version files may have CR characters that will prevent rbenv from correctly parsing the Ruby version. Discard those characters when reading the file.
finding_local_version_file is extremely slow, when working directory is under the UNC path.
Because //host/.rbenv-version and //.rbenv-version do not exist, but testing them is so slow.
It's the reason to make a serious delay of the response, when the Ruby runs with a current working directory under the UNC path under Cygwin environment.
A response of before applying this patch.
//somehost/somedir $ time ruby -e "exit"
real 0m13.922s
user 0m0.168s
sys 0m0.287s
A response of after applying this patch.
//somehost/somedir $ time ruby -e "exit"
real 0m0.721s
user 0m0.153s
sys 0m0.319s
The `pwd` may return relative path if the `$PWD` is badly declared
in bash/zsh (e.g. `PWD="." bash`). To avoid the infinite loop in
`find_local_version_file()`, stop finding the version file if the
target paths are same consecutively.
