[DRE-maint] Bug#895610: ruby-fastimage requires internet access during the build

[Adrian Bunk]

Source: ruby-fastimage
Version: 2.1.1-1
Severity: serious

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

...
┌──────────────────────────────────────────────────────────────────────────────┐
│ Run tests for ruby2.5 from debian/ruby-test-files.yaml                       │
└──────────────────────────────────────────────────────────────────────────────┘

RUBYLIB=/build/1st/ruby-fastimage-2.1.1/debian/ruby-fastimage/usr/lib/ruby/vendor_ruby:. GEM_PATH=debian/ruby-fastimage/usr/share/rubygems-integration/all:/var/lib/gems/2.5.0:/usr/lib/x86_64-linux-gnu/rubygems-integration/2.5.0:/usr/share/rubygems-integration/2.5.0:/usr/share/rubygems-integration/all ruby2.5 -ryaml -e YAML.load_file\(\"debian/ruby-test-files.yaml\"\).each\ \{\ \|f\|\ require\ f\ \}
Loaded suite -e
Started
.........................................F
===============================================================================
Failure: test_should_work_with_domains_with_underscores(FastImageTest)
/build/1st/ruby-fastimage-2.1.1/test/test.rb:377:in `test_should_work_with_domains_with_underscores'
     374:   end
     375: 
     376:   def test_should_work_with_domains_with_underscores
  => 377:     assert_equal :gif, FastImage.type("http://foo_bar.switchstep.com/images/p.gif")
     378:   end
     379: 
     380:   def test_should_return_content_length_for_data_uri_images
<:gif> expected but was
<nil>

diff:
? :gif
? n  l
===============================================================================
.

Finished in 1.178488701 seconds.
------
43 tests, 477 assertions, 1 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications
97.6744% passed
------
36.49 tests/s, 404.76 assertions/s
ERROR: Test "ruby2.5" failed. Exiting.
dh_auto_install: dh_ruby --install /build/1st/ruby-fastimage-2.1.1/debian/ruby-fastimage returned exit code 1
make: *** [debian/rules:15: binary] Error 1