[DRE-maint] Bug#999650: ruby-oily-png FTBFS on 32bit

[Adrian Bunk]

Source: ruby-oily-png
Version: 1.2.1~dfsg-2
Severity: serious
Tags: ftbfs

https://buildd.debian.org/status/package.php?p=ruby-oily-png

...
Failures:

  1) OilyPNG::Color#compose_quick should use the background color as is when a fully transparent pixel is given as foreground color
     Failure/Error: expect(compose_quick(@fully_transparent, @white)).to be(@white)

       expected #<Integer:820> => 4294967295
            got #<Integer:830> => 4294967295

       Compared using equal?, which compares object identity,
       but expected and actual are not the same object. Use
       `expect(actual).to eq(expected)` if you don't care about
       object identity in this example.
     # ./spec/color_spec.rb:24:in `block (3 levels) in <top (required)>'

  2) OilyPNG::Color#compose_quick should compose pixels correctly
     Failure/Error: expect(compose_quick(@non_opaque, @white)).to be(0x9fc2d6ff)

       expected #<Integer:840> => 2680346367
            got #<Integer:850> => 2680346367

       Compared using equal?, which compares object identity,
       but expected and actual are not the same object. Use
       `expect(actual).to eq(expected)` if you don't care about
       object identity in this example.
     # ./spec/color_spec.rb:28:in `block (3 levels) in <top (required)>'

  3) OilyPNG::Color#compose_quick should compose colors exactly the same as ChunkyPNG
     Failure/Error: expect(compose_quick(fg, bg)).to be(ChunkyPNG::Color.compose_quick(fg, bg))

       expected #<Integer:860> => 2126858483
            got #<Integer:870> => 2126858483

       Compared using equal?, which compares object identity,
       but expected and actual are not the same object. Use
       `expect(actual).to eq(expected)` if you don't care about
       object identity in this example.
     # ./spec/color_spec.rb:33:in `block (3 levels) in <top (required)>'

Finished in 0.36245 seconds (files took 0.22531 seconds to load)
146 examples, 3 failures, 18 pending

Failed examples:

rspec ./spec/color_spec.rb:23 # OilyPNG::Color#compose_quick should use the background color as is when a fully transparent pixel is given as foreground color
rspec ./spec/color_spec.rb:27 # OilyPNG::Color#compose_quick should compose pixels correctly
rspec ./spec/color_spec.rb:31 # OilyPNG::Color#compose_quick should compose colors exactly the same as ChunkyPNG

/usr/bin/ruby2.7 -I/usr/share/rubygems-integration/all/gems/rspec-support-3.9.3/lib:/usr/share/rubygems-integration/all/gems/rspec-core-3.9.2/lib /usr/share/rubygems-integration/all/gems/rspec-core-3.9.2/exe/rspec --pattern ./spec/\*\*/\*_spec.rb --format documentation failed
ERROR: Test "ruby2.7" failed. Exiting.
dh_auto_install: error: dh_ruby --install /<<BUILDDIR>>/ruby-oily-png-1.2.1\~dfsg/debian/ruby-oily-png returned exit code 1
make: *** [debian/rules:8: binary-arch] Error 25