cp --debug should show when `sparse detection: SEEK_HOLE`

[sylvestre]

with our:

$ truncate -s16M file.sparse_
$ ./target/debug/cp --debug --reflink=never file.sparse_ file.sparse_.cp    
'file.sparse_' -> 'file.sparse_.cp'
copy offload: unknown, reflink: no, sparse detection: no

with GNU:

$ truncate -s16M file.sparse_
$ /usr/bin/cp --debug --reflink=never file.sparse_ file.sparse_.cp
'file.sparse_' -> 'file.sparse_.cp'
copy offload: unknown, reflink: no, sparse detection: SEEK_HOLE

Used https://github.com/coreutils/coreutils/blob/master/init.cfg#L555
and will unblock some tests like GNU/tests/cp/sparse-2

We have the definition but I don't think it is used anywhere:

coreutils/src/uu/cp/src/cp.rs

Line 305 in be82200

SeekHole,

[shinigami-777]

Hello @sylvestre . I would like to work on this issue. Can you please guide me a bit on what files need to be changed as I am new to this.

[sylvestre]

With pleasure.
Finding the file is part of the exercice :) should not be hard

[AbhinavMir]

I'm not sure if I'm hallucinating, but when I last contributed, I think there was a method to hot-reload to test these things. Can I just install, rebuild and reinstall to see if it works as I expect?