dh-autoreconf stopped because of md5sum 123 error

Binary package hint: dh-autoreconf

Happened with evolution package (lp:~ubuntu-desktop/evolution/ubuntu).
- remove the 99_autoreconf.patch
- add autoreconf.mk rules + build-dep.

When building, we get an error on that part:
dh_autoreconf
md5sum: pop: No such file or directory
md5sum: pop: No such file or directory
md5sum: imap: No such file or directory
md5sum: imap: No such file or directory
md5sum: free: No such file or directory
md5sum: pop: No such file or directory
md5sum: ssl: No such file or directory
md5sum: pop: No such file or directory
md5sum: imap: No such file or directory
md5sum: ssl: No such file or directory
md5sum: imap: No such file or directory
dh_autoreconf: find ! -ipath "./debian/*" -a -type f | xargs md5sum > debian/autoreconf.before returned exit code 123
make: *** [post-patches] Error 9

Indeed, md5sum, as it can't find one args, gives a 123 error code. And some file contains spaces.

find ! -path "./debian/*" -a -type f | xargs md5sum > debian/autoreconf.before
md5sum: pop: No such file or directory
md5sum: pop: No such file or directory
md5sum: imap: No such file or directory
md5sum: imap: No such file or directory
md5sum: free: No such file or directory
md5sum: pop: No such file or directory
md5sum: ssl: No such file or directory
md5sum: pop: No such file or directory
md5sum: imap: No such file or directory
md5sum: ssl: No such file or directory
md5sum: imap: No such file or directory
$ echo $?
123

You should rather use:
find ! -path "./debian/*" -a -type f -exec md5sum {} \; > debian/autoreconf.before

Fixing in ubuntu and forwarding to debian