build failures on mipsel

[Tomi Ollila]

On Wed, Jun 06 2018, Daniel Kahn Gillmor wrote:

> On Mon 2018-06-04 17:52:46 -0400, Daniel Kahn Gillmor wrote:
>> I've tried to replicate the problem over on eller.debian.org (the mipsel
>> porterbox) but when i build 0.27~rc1 over there in an schroot, i don't
>> even get to T357 because the emacs_fcc_message() function hangs in this
>> loop (is this known to not work in an schroot or under similar
>> situations?):
>
> This problem appears to be related to some bad interaction with
> screen(1) inside a sid chroot on eller.  i note that bash also has
> problems with command line editing in that environment as well.
>
> I'm now running inside of tmux instead, and that problem doesn't happen
> any more.
>
> Furthermore, i can't replicate the failure from the buildd when building
> on eller either.  So neither bremner nor i were able to replicate the
> problem.
>
> mipsel porters, do you have any suggestions for next-step debugging?


This is the line to start emacs

  # start a detached session with an emacs server
  # user's TERM (or 'vt100' in case user's TERM is known dumb
  # or unknown) is given to dtach which assumes a minimally
  # VT100-compatible terminal -- and emacs inherits that

  TERM=$SMART_TERM dtach -n "$TEST_TMPDIR/emacs-dtach-socket.$$" \
          sh -c "stty rows 24 cols 80; exec '$TMP_DIRECTORY/run_emacs' \
                  --no-window-system \
                  $load_emacs_tests \
                  --eval '(setq server-name \"$server_name\")' \
                  --eval '(server-start)' \
                  --eval '(orphan-watchdog $$)'" || return

my first guess: SMART_TERM is 'screen', and terminfo for that is missing

if not, then some TTY problem, which may break dtach, and if not dtach,
then emacs

my usual try is strace(1): 

  TERM=$SMART_TERM strace -f dtach -n "$TEST_TMPDIR/emacs-dtach-socket.$$" \
          sh -c "stty rows 24 cols 80; exec '$TMP_DIRECTORY/run_emacs' \
                  --no-window-system \
                  $load_emacs_tests \
                  --eval '(setq server-name \"$server_name\")' \
                  --eval '(server-start)' \
                  --eval '(orphan-watchdog $$)'" &

(have to be run in background as strace -f will not exit until every child
program have exited...)

and then comb through strace output (-o option to strace may be useful...).

>
>        --dkg