Can't compile from within emacs if $EMACS is not set.

[rosekunkel]

The makefile uses the $EMACS environment variable to find emacs if it is present, or falls back to emacs if it is not. However, emacs seems to set the $EMACS environment variable to t for all of its subshells if it does not already exist. The result is that running make from an emacs shell or with M-x compile fails with /bin/sh: t: command not found.

[gracjan]

Is there a way to find out the real path to currently running Emacs?

[rosekunkel]

Good question! I can get the parent PID from a shell with bash's $PPID, and find the path to the parent with /proc/$PPID/exe. But that breaks down if we're in a sub-subshell. I don't know if there's a good solution for arbitrarily deep subshells. I don't know if this really matters, though, because if $EMACS is set, it's passed through, and if it's not set, the makefile uses "emacs". Using the current emacs path could cause different behavior than running make from the command line, which doesn't seem desirable.

[gracjan]

@wkunkel: I see that your fix actually fixes the issue, so merged. Thanks.