This reverts commit adee5315265cc46aa6a3057071527abb16e1cd94.
Turns out one of the "other things" is a dealbreaker.
We only create kegs using a formula's canonical name. However, we do not
check that this is the case when mapping existing kegs back to formula
objects, and thus a keg with a name that happens to be an alias can fool
Homebrew into thinking the canonically-named keg exists.
So anything that enumerates kegs and then tries to do stuff with the
resulting formula objects will just break. This is obviously worse than
the debugger being broken, so reverting this for the time being.
The Readline class clashes with the Readline module from the Ruby
stdlib. This has mostly worked, but with the recent debugging support's
integration of IRB, it is no longer possible for them to coexist. So we
need to rename it.
The implications of this are:
- Anything that depends on readline will reinstall it as
"gnu-readline". Anything already installed will continue to function.
- "brew upgrade readline" will say "gnu-readline not installed", as
"readline" is now an alias.
- Probably other things.
So there are some downsides, but we will just have to deal with them.
FixesHomebrew/homebrew#15776.
