Lintian tag information: patch-system-but-no-source-readme (type: warning)

Description (from lintian-explain-tags)

This package build-depends on a patch system such as dpatch or quilt, but
there is no debian/README.source file. This file is recommended for any
package where dpkg-source -x does not result in the preferred form for
making modifications to the package.

If you are using quilt and the package needs no other special handling
instructions, you may want to add a debian/README.source referring to
/usr/share/doc/quilt/README.source. Similarly, you can refer to
/usr/share/doc/dpatch/README.source.gz for dpatch.

Please refer to Source package handling: debian/README.source (Section
4.14) in the Debian Policy Manual for details.

Visibility: warning
Show-Always: no
Check: debian/patches

Show affected packages