view tests/test-check-shbang.t @ 37212:f09a2eab11cf

server: add an error feedback mechanism for when the daemon fails to launch

There's a recurring problem on Windows where `hg serve -d` will randomly fail to
spawn a detached process.  The reason for the failure is completely hidden, and
it takes hours to get a single failure on my laptop.  All this does is redirect
stdout/stderr of the child to a file until the lock file is freed, and then the
parent dumps it out if it fails to spawn.

I chose to put the output into the lock file because that is always cleaned up.
There's no way to report errors after that anyway.  On Windows, killdaemons.py
is roughly `kill -9`, so this ensures that junk won't pile up.

This may end up being a case of EADDRINUSE.  At least that's what I saw spit out
a few times (among other odd errors and missing output on Windows).  But I also
managed to get the same thing on Fedora 26 by running test-hgwebdir.t with
--loop -j10 for several hours.  Running `netstat` immediately after killing that
run printed a wall of sockets in the TIME_WAIT state, which were gone a couple
seconds later.  I couldn't match up ports that failed, because --loop doesn't
print out the message about the port that was used.  So maybe the fix is to
rotate the use of HGPORT[12] in the tests.  But, let's collect some more data
first.

#require test-repo

  $ . "$TESTDIR/helpers-testrepo.sh"
  $ cd "`dirname "$TESTDIR"`"

look for python scripts that do not use /usr/bin/env

  $ testrepohg files 'set:grep(r"^#!.*?python") and not grep(r"^#!/usr/bi{1}n/env python") - **/*.t'
  [1]

In tests, enforce $PYTHON and *not* /usr/bin/env python or similar:
  $ testrepohg files 'set:grep(r"#!.*?python") and **/*.t' \
  > -X tests/test-check-execute.t \
  > -X tests/test-check-module-imports.t \
  > -X tests/test-check-pyflakes.t \
  > -X tests/test-check-shbang.t
  [1]

The above exclusions are because they're looking for files that
contain Python but don't end in .py - please avoid adding more.

look for shell scripts that do not use /bin/sh

  $ testrepohg files 'set:grep(r"^#!.*/bi{1}n/sh") and not grep(r"^#!/bi{1}n/sh")'
  [1]