Can't modify frozen String

[RoxasShadow]

Hello.

Most of the times happens that either me or my CI can't build this gem.

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    can't modify frozen String

Gem files will remain installed in /Users/giovanni/Desktop/honeypot/vendor/bundle/ruby/2.3.0/gems/shoulda-callback-matchers-1.1.4
for inspection.
Results logged to
/Users/giovanni/Desktop/honeypot/vendor/bundle/ruby/2.3.0/extensions/x86_64-darwin-16/2.3.0/shoulda-callback-matchers-1.1.4/gem_make.out

Ruby is 2.3.3p222, Rails is 4.2.7.1

Unfortunately I can't find the location where this frozen string modification is happening 😞

[g3d]

:+1: same issues, happens on CI inside docker

ruby: 2.4.0

[g3d]

Issue was fixed by adding gem update --system before bundle install step