[DRE-maint] Bug#890257: ruby-grape: FTBFS with ruby2.3 and ruby-rack-test 0.7

[Cédric Boutillier]

Source: ruby-grape
Version: 0.16.2-2
Severity: serious
Justification: fails to build from source

Dear Maintainer,

The version 0.16.2-2 fails to build with ruby2.3. According to
ci.debian.net, this has been happening since Sept, 7 2018
https://ci.debian.net/data/autopkgtest/unstable/amd64/r/ruby-grape/20170907_031907/log.gz
This coincides with the transition to ruby-activesupport 2:4.2.9-3
which itself induced the transition from ruby-rack-test 0.6.3 to 0.7.

Using ruby-rack-test 0.6.3 from stretch makes the tests pass with
ruby2.3 (they fail with ruby2.5, but it is another problem).

Cheers,

Cédric

-- System Information:
Debian Release: buster/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.14.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE= (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

-- no debconf information