[krbdev.mit.edu #8863] krb5int_key_delete: Assertion `destructors_set[keynum] == 1' failed.

[Spencer Malone via RT]

Thu Jan 09 14:16:32 2020: Request 8863 was acted upon.
 Transaction: Ticket created by malone.spencer at gmail.com
       Queue: krb5
     Subject: krb5int_key_delete: Assertion `destructors_set[keynum] == 1' failed.
       Owner: Nobody
  Requestors: malone.spencer at gmail.com
      Status: new
 Ticket <URL: https://krbdev.mit.edu/rt/Ticket/Display.html?id=8863 >


Heyo! In our apache/httpd instances, we're regularly seeing the following
cause segfaults:

httpd: threads.c:395: krb5int_key_delete: Assertion
`destructors_set[keynum] == 1' failed.
We don't directly utilize krb5, but the library is pulled in by a few
transient dependencies.
After digging around on the net, it seems we aren't alone:
https://stackoverflow.com/questions/54213685/apache-seg-fault-krb5int-key-delete-assertion-destructors-setkeynum-1-fail

I tried to dump all apache modules that could be loading libkrb5 and came
up with...

/etc/httpd/modules/libphp7.so
	libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f4f35f65000)
	libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f4f34839000)
/etc/httpd/modules/libphp7-zts.so
	libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007ff228114000)
	libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007ff226c04000)
/etc/httpd/modules/mod_ssl.so
	libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f0c0c7fa000)
	libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f0c0bf9d000)

Any thoughts on a potential solution or cause?