Record function -- path resets after Asterisk build

In the process of doing dialplan development I have come across a context that no longer functions correctly. The part of the context that fails is very simple:

   exten => record, n, Record(/my/broadcast/dir/${filename}:wav)

When executed, the CLI output (simplified) looks like:

Executing Record("SIP/Blah.somehost-0000007", "/my/broadcast/dir/mySoundfile:wav")
WARNING: file.c:1164 ast_writefile: Unable to open file /opt/asterisk-1..../var/spool//asterisk/tmp/_my_broadcast_dir_mySoundfile.wav: No such file or directory
WARNING: app_record Could not create file /my/broadcast/dir/mySoundfile
(Several more errors, all caused by the initial failure)

My Asterisk was rebuilt a few days ago, and prior to this, the Record worked just fine because it opened the file in the location I specified. Something about the rebuild broke this. It seems that now is only using paths relative to /opt/asterisk-1…/var/spool/asterisk/tmp/. What aspect of configuration lets me make this correct?