Comment 5 for bug 44019

Robin Smidsrød wrote:
> How would I go about setting up some mod_perl tracing (mods-available/perl.conf) to get some more details on this problem. I've read the docs on perl.apache.org about tracing, but I'm unsure how to exactly use it. I tried to enable all tracing, but for some reason it doesn't do as I intend.
>
> Do one of you have a working apache/mod_perl trace setup that traps this kind of error?

Please try the following:
download mod-perl:
$ apt-get source libapache2-mod-perl2
get the build dependencies:
$ apt-get build-dep libapache2-mod-perl2

$ cd libapache2-mod-perl2-2.0.2

Edit debian/rules to set MP_USE_GTOP to 0 (compilation error otherwise)
and MP_TRACE to 1.

Preferably, install the fakeroot package, then
$ DEB_BUILD_OPTIONS="noopt nostrip" dpkg-buildpackage -rfakeroot

Install the resulting package...

Add
PerlTrace all
to your configuration.

When running, you should see extra tracing in the apache2 error log.
Check in the error log for
"localizing", referring to the name of an environment variable.

This might show a use of "local %ENV" somewhere in a module, as this is
a known reproducible crash (I can't access the patch for it at the
moment because the apache repository is down at the moment).

Otherwise, there's another known reason for a crash in this area: if
your $r object is a closure, the code may fail to work, and crash.

If neither suggestion helps, please send the backtrace resulting from
the crash.