Installer causes error when run multiple times

[jelaniwoods]

When I tried to rails g web_git:install in a base-rails-based Gitpod, I got the below error message. Snapshot:

https://gitpod.io#snapshot/68d150dd-2f4b-416a-a054-dd48915de313

=> Booting Puma
=> Rails 6.0.3.2 application starting in development 
=> Run `rails server --help` for more startup options
Exiting
Traceback (most recent call last):
        38: from bin/rails:3:in `<main>'
        37: from bin/rails:3:in `load'
        36: from /workspace/base-rails/bin/spring:15:in `<top (required)>'
        35: from /home/gitpod/.rvm/rubies/ruby-2.6.6/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        34: from /home/gitpod/.rvm/rubies/ruby-2.6.6/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
        33: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `<top (required)>'
        32: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `load'
        31: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/bin/spring:49:in `<top (required)>'
        30: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/client.rb:30:in `run'
        29: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/client/command.rb:7:in `call'
        28: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `call'
        27: from /home/gitpod/.rvm/ruby-2.6.6/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `load'
        26: from /workspace/base-rails/bin/rails:9:in `<top (required)>'
        25: from /home/gitpod/.rvm/ruby-2.6.6/gems/activesupport-6.0.3.2/lib/active_support/dependencies.rb:324:in `require'
        24: from /home/gitpod/.rvm/ruby-2.6.6/gems/activesupport-6.0.3.2/lib/active_support/dependencies.rb:291:in `load_dependency'
        23: from /home/gitpod/.rvm/ruby-2.6.6/gems/activesupport-6.0.3.2/lib/active_support/dependencies.rb:324:in `block in require'
        22: from /home/gitpod/.rvm/ruby-2.6.6/gems/bootsnap-1.4.7/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
        21: from /home/gitpod/.rvm/ruby-2.6.6/gems/bootsnap-1.4.7/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
        20: from /home/gitpod/.rvm/ruby-2.6.6/gems/bootsnap-1.4.7/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        19: from /home/gitpod/.rvm/ruby-2.6.6/gems/bootsnap-1.4.7/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
        18: from /home/gitpod/.rvm/ruby-2.6.6/gems/bootsnap-1.4.7/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
        17: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands.rb:18:in `<main>'
        16: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/command.rb:46:in `invoke'
        15: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/command/base.rb:69:in `perform'
        14: from /home/gitpod/.rvm/ruby-2.6.6/gems/thor-1.0.1/lib/thor.rb:392:in `dispatch'
        13: from /home/gitpod/.rvm/ruby-2.6.6/gems/thor-1.0.1/lib/thor/invocation.rb:127:in `invoke_command'
        12: from /home/gitpod/.rvm/ruby-2.6.6/gems/thor-1.0.1/lib/thor/command.rb:27:in `run'
        11: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands/server/server_command.rb:138:in `perform'
        10: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands/server/server_command.rb:138:in `tap'
         9: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands/server/server_command.rb:147:in `block in perform'
         8: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands/server/server_command.rb:37:in `start'
         7: from /home/gitpod/.rvm/ruby-2.6.6/gems/railties-6.0.3.2/lib/rails/commands/server/server_command.rb:77:in `log_to_stdout'
         6: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/server.rb:422:in `wrapped_app'
         5: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/server.rb:249:in `app'
         4: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/server.rb:349:in `build_app_and_options_from_config'
         3: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/builder.rb:66:in `parse_file'
         2: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/builder.rb:105:in `load_file'
         1: from /home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/builder.rb:116:in `new_from_string'
/home/gitpod/.rvm/ruby-2.6.6/gems/rack-2.2.3/lib/rack/builder.rb:116:in `eval': config.ru:15: syntax error, unexpected end, expecting end-of-input (SyntaxError)

Originally posted by @raghubetina in #100 (comment)