allows building bundix but most ruby gems still fail with
```
++ gem install --local --force --http-proxy http://nodtd.invalid --ignore-dependencies --install-dir /nix/store/...-ruby-aarch64-unknown-linux-gnu2.7.6-nio4r-2.5.8-aarch64-unknown-linux-gnu/lib/ruby/gems/2.7.0
--build-root / --backtrace --no-env-shebang -N /nix/store/...-nio4r-2.5.8.gem --
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 8: require: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 9: require: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 10: require: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 12: required_version: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 14: unless: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 15: abort: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 16: end: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 18: args: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 20: begin: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 21: Gem::GemRunner.new.run: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 22: rescue: command not found
/nix/store/...-ruby-aarch64-unknown-linux-gnu-2.7.6/bin/gem: line 23: exit: e.exit_code: numeric argument required
```
@ruby maintainers: please feel free to revert this and let me know,
should it cause any problems.
Stuff that's in the store shouldn't be writable! So let's disable
Bundler's requires_sudo? method, which checks if some files are
writable and suggests using sudo if not, entirely.
Previously, schleuder-cli would print to stderr when run:
Following files may not be writable, so sudo is needed:
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/bin
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/bin
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/build_info
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/bundler
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/cache
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/doc
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/extensions
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/gems
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/plugins
/nix/store/qg40x0ysrf9x6sag6qgb1klg87lskdp5-schleuder-cli-0.1.0/lib/ruby/gems/2.7.0/specifications
Otherwise you end up with a derivation that refers to the original
path (which is not in the Nix store and not accessible to
builders). This caused the derivation paths for the docbookrx package
(removed on master) to depend on the location of the nixpkgs source
tree.
This was ignored before. Now that it's passed through, it's possible
to do
(bundlerEnv {
name = "...";
gemdir = ./.;
document = [ "ri" ];
}).env
and get an environment where ri can be used to read gem documentation.
