What does "pop from empty list" mean?

[Alexandre_Nizou]

Using diff in a search, the interface shows the following message:

Pop from empty string

The search is the following:

index=main source="/etc/syslog-ng/syslog-ng.conf" | diff

Source exists in the correct index, and without the diff it will show raw content revisions of said file. What am I doing wrong?

Thanks.

[sideview]

Hm. that's very strange.

Out of curiosity what happens if you really only give diff the most recent 2 revisions, like so:

index=main source="/etc/syslog-ng/syslog-ng.conf" | head 2 | diff

It shouldnt make a difference but I'm wondering if it hits something deeper in the events that is triggering some bug.

Another thing to troubleshoot would be comparing different positions besides the first two rows.

index=main source="/etc/syslog-ng/syslog-ng.conf" | diff position1=10 position2=11

[Alexandre_Nizou]

Did not change a thing, yet when I do a 'index=main source="/etc/syslog-ng/syslog-ng.conf"' I do see 2 different revisions of the file.