brush is a shell written in Rust that implements POSIX shell behavior
and a large subset of Bash.  It is intended to run existing scripts and
.bashrc files, and includes an interactive line editor with syntax
highlighting, history and programmable completion.

This package installs the shell as ${PREFIX}/bin/brush and as
${PREFIX}/bin/bash, registers both in /etc/shells, conflicts with
shells/bash, and declares shells/bash as a secondary pkgpath, so the
package tools accept it as a provider of that path.  The GNU package
must not be installed at the same time.

Because the file name is the same, ports that invoke bash(1) need no
source changes to use this package; their build dependency on
shells/bash only has to be pointed at shells/brush.

brush is not a complete Bash implementation: select, wait -n, disown
and logout are not implemented, signal traps are still in progress, and
there are known edge cases in IFS splitting, printf and alias
expansion.  Upstream maintains a compatibility reference at
https://github.com/reubeno/brush/blob/main/docs/reference/compatibility.md
and validates the shell against bash with a large compatibility test
suite.  Do not install it as a system-wide replacement for shells/bash
without testing the affected scripts.
