The --tags-absolute option is incompatible with reading files from stdin.

[ntc2]

Doing

hasktags --tags-absolute STDIN

results in the error

hasktags: STDIN: canonicalizePath: does not exist (No such file or directory)

because canonicalizePath is applied to all files at

hasktags/src/Main.hs

Line 77 in 7a492fc

then sequence $ map canonicalizePath files_or_dirs_unexpanded

.

It think the correct behavior is to first convert STDIN into a list of files read from stdin and then call canonicalizePath. If you agree with this solution and don't want to implement it yourself, I would be happy to submit a pull request.

[ntc2]

Work around on systems with readlink -f (Linux has it but Mac does not, I think):

<generate files> | xargs -n1 readlink -f | hasktags STDIN