[9fans] MirOS ksh (mksh) building out-of-the box on Plan9/APE

[Jens Staal <staal1978@gmail.com>]

Dear all,

From yesterday upstream mksh (cvs and future R48 and onwards) builds out
of the box on Plan9 simply by:

ape/psh
./Build.sh

One issue remains and that is that the shell will get "stuck" after
executing an external command. To build a working shell, there is a
temporary work-around by issuing:

CFLAGS="-DMKSH_NOPROSPECTOFWORK" ./Build.sh

This disables a number of features in the shell.

I have uploaded an R47 build with the modified Build.sh (with
-DMKSH_NOPROSPECTOFWORK)
at /n/sources/contrib/staal1978/pkg/mksh-R47.tbz.

In order to get a fully-functional mksh, something needs to be fixed
host-side. A good guess is that it is the way APE handles SIGCHLD,
since the same "freezing" has occurred on a number of other ports of
mksh:

http://www.mail-archive.com/miros-mksh@mirbsd.org/msg00215.html

Is there interest in fixing SIGCHLD on APE and if so, what would be the
best approach?

If there is interest, it would thus be entirely possible to have an
upstream, modern and mantained ksh shell which builds unmodified for APE
(possibly as replacement of the old pdksh port now acting as "sh").
The mksh shell is used in many different contexts, most notably as
shell in the more modern versions of Android.