Re: "lein repl" malfunctions in Emacs (24.3.1) subprocess?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 13 Apr 2015 14:23:47 -0700 (PDT)
> From: cohagan@acm.org
> 
> I'm trying to use Emacs as my dev environment for Clojure programming under Windows 8.1. When I open a subprocess (via M-x shell) I get a command prompt as expected. I can then run "lein test" and my unit tests are run as expected -- with output to the shell buffer as expected.
> 
> If, however, I enter "lein repl" then the REPL starts as expected, but is non responsive. For example, if I enter (+ 1 2) at the user=> prompt (followed by Enter) I get no response at all.  The input isn't echoed (as expected) and no output at all appears.
> 
> Note that "lein repl" runs fine at a normal command prompt (or within a subprocess buffer in Epsilon (an Emacs clone.)) This problem occurs on 3 different machines.
> 
> This has worked for me in the past so obviously something has broken, but I haven't a clue what it might be or how to troubleshoot.

Likely a buffering issue.  Emacs on Windows runs subprocesses via a
pipe, and many programs then buffer their stdout fully, unlike line
buffering they use when run from a shell prompt.

If "lein repl", whatever that is, has an option to control buffering,
or there's a variable you can set or command you can issue to that
effect inside "lein repl", they will likely fix the problem.