errorformat: Trailing characters. Cannot load Grepper output from a file into quickfix

Question

I get Trailing characters error with set errorformat when trying to use quickfix:

This is a sample line from a file 20240527-grep.txt that I would load into quickfix. Note, I obtained this output from a Grepper command:

pages/20230817-Beyza-GG.md|19 col 3| - TODO #p/beyza: Takip edelim

This is the command to load the above file into quickfix:

cfile ~/prj/collabryio/cldocs/cllogseq/20240527-grep.txt

This is the output in quickfix:

|| pages/20230817-Beyza-GG.md|19 col 3| - TODO #p/beyza: Takip edelim

I set errorformat with the following commands but I get Trailing characters error:

set errorformat+=%f|%l col %c|%m
# E488: Trailing characters: col %c
set errorformat^=%f|%l col %c|%m
# E488: Trailing characters: col %c

Now, I load the file into quickfix again:

cfile ~/prj/collabryio/cldocs/cllogseq/20240527-grep.txt

Now the output in quickfix becomes empty totally:

Answer 1

You have to escape the space and the pipe |:

set errorformat+=%f\|%l\ col\ %c\|%m

You could be interested to the alternative form:

let &errorformat .= ',%f|%l col %c|%m'