[DRE-maint] Bug#903341: ruby-rubymail: FTBFS in buster/sid (dh_installdocs: Cannot find "README")

[Santiago Vila]

Package: src:ruby-rubymail
Version: 1.1.3-1
Severity: serious
Tags: ftbfs

Dear maintainer:

I tried to build this package in buster but it failed:

--------------------------------------------------------------------------------
[...]
 debian/rules build-indep
dh build-indep --buildsystem=ruby --with ruby
   dh_update_autotools_config -i -O--buildsystem=ruby
   dh_auto_configure -i -O--buildsystem=ruby
	dh_ruby --configure
   debian/rules override_dh_auto_build
make[1]: Entering directory '/<<PKGBUILDDIR>>'
dh_auto_build
	dh_ruby --build
   dh_ruby --build
rake rdoc
Parsing sources...
  5% [ 1/19]  ChangeLog
 10% [ 2/19]  README.md

[... snipped ...]

    test_transparency_absolute_05:			.: (0.000842)
    test_transparency_absolute_06:			.: (0.002141)
    test_transparency_message_01:			.: (0.001448)
    test_transparency_message_02:			.: (0.001710)
    test_transparency_message_03:			.: (0.001168)
    test_transparency_message_04:			.: (0.000559)
    test_transparency_message_05:			.: (0.000655)
    test_transparency_message_06:			.: (0.001684)
    test_transparency_nested_multipart:			.: (0.001611)
    test_transparency_rfc822:				.: (0.001081)
    test_transparency_simple_mime:			.: (0.001027)
  TestTestBase: 
    test_cleandir:					.: (0.000897)
    test_file_contains:					.: (0.000511)
    test_name:						.: (0.000259)
    test_ruby_program:					.: (0.000272)
    test_scratch_dir:					.: (0.000263)
    test_scratch_filename:				.: (0.000313)
    test_string_as_file:				.: (0.000787)
  TextRMailMBoxReader: 
    test_mbox_chunksize:				.: (0.012013)
    test_mbox_odd:					.: (0.000415)
    test_mbox_randomly:					.: (0.086029)
    test_mbox_s_new:					.: (0.000324)
    test_mbox_simple:					.: (0.000422)
  TextRMailParserPushbackReader: 
    test_pushback:					.: (0.000352)

Finished in 0.727013135 seconds.
-------------------------------------------------------------------------------
168 tests, 24214 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
100% passed
-------------------------------------------------------------------------------
231.08 tests/s, 33306.14 assertions/s

┌──────────────────────────────────────────────────────────────────────────────┐
│ dh_ruby --install finished                                                   │
└──────────────────────────────────────────────────────────────────────────────┘

# Remove script files from ruby-rubymail-doc
rm -rf /<<PKGBUILDDIR>>/debian/ruby-rubymail-doc/usr/lib
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
   dh_install -i -O--buildsystem=ruby
   dh_installdocs -i -O--buildsystem=ruby
dh_installdocs: Cannot find (any matches for) "README" (tried in .)

debian/rules:6: recipe for target 'binary-indep' failed
make: *** [binary-indep] Error 2
dpkg-buildpackage: error: fakeroot debian/rules binary-indep subprocess returned exit status 2
--------------------------------------------------------------------------------

The build was made with "dpkg-buildpackage -A" in my autobuilder.
Most probably, it also fails here in reproducible builds:

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/ruby-rubymail.html

[ Note: There has been a recent change in debhelper behaviour, the current
  behaviour is the intended one. See Bug #903133 for details ].

Thanks.