[DRE-maint] Bug#981850: Failed: rspec-core, rspec-support

[Ritesh Raj Sarraf]

Package: ruby-rspec
Version: 3.9.0c2e2m1s3-1
Severity: serious
Tags: ftbfs
Justification: fails to build from source

Dear Maintainer,

During a rebuild of the package for Bullseye, it is seen that the
package fails to build. The build failure snippet is below. It is also
noticed that the same build failure is seen on the Reproducible Builds.

```
[  294s] Finished in 2.23 seconds (files took 0.50425 seconds to load)
[  294s] 538 examples, 3 failures, 1 pending
[  294s]
[  294s] Failed examples:
[  294s]
[  294s] rspec ./spec/rspec/support/differ_spec.rb:315 # RSpec::Support::Differ#diff outputs unified diff message of two hashes with differing encoding
[  294s] rspec ./spec/rspec/support/differ_spec.rb:328 # RSpec::Support::Differ#diff outputs unified diff message of two hashes with encoding different to key encoding
[  294s] rspec ./spec/rspec/support/differ_spec.rb:158 # RSpec::Support::Differ#diff uses the default external encoding when the two strings have incompatible encodings
[  294s]
[  294s] Randomized with seed 8873
[  294s]
[  295s] cd -
[  295s] Failed: rspec-core, rspec-support
[  295s] ERROR: Test "ruby2.7" failed. Exiting.
[  295s] dh_auto_install: error: dh_ruby --install /usr/src/packages/BUILD/debian/tmp returned exit code 1
[  295s] make: *** [debian/rules:99: binary] Error 25
[  295s] dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
```


-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (990, 'testing'), (500, 'stable-updates'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-3-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_USER
Locale: LANG=en_IN.UTF-8, LC_CTYPE=en_IN.UTF-8 (charmap=UTF-8), LANGUAGE=en_US
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages ruby-rspec depends on:
ii  ruby                     1:2.7+2
pn  ruby-rspec-core          <none>
pn  ruby-rspec-expectations  <none>
pn  ruby-rspec-mocks         <none>

ruby-rspec recommends no packages.

ruby-rspec suggests no packages.