fixing installing deps for older rubies

Gemfile

@@ -10,28 +10,30 @@ gem "rspec", "~> 3.5"
 
 group :development do
   gem "pry"
-end
-
-platforms :mri do
   gem "pry-byebug", require: false
-  gem "stackprof", require: false
-  gem "xorcist", require: false
 end
 
+gem "xorcist", require: false
+
+gem "parallel", "< 1.19.0", require: false if RUBY_VERSION < "2.4"
 gem "rubocop", "0.52.1", require: false
 
 gem "rbs", require: false if RUBY_VERSION >= "3.0"
 
-if RUBY_VERSION < "2.2"
+if RUBY_VERSION < "2.2.0"
+  gem "celluloid", "~> 0.17.3"
   gem "celluloid-io", "~> 0.17.3"
   gem "nio4r", "~> 1.2"
   gem "simplecov", "< 0.11.0", require: false
 else
   gem "celluloid-io", "~> 0.17"
 
-  if RUBY_VERSION < "2.3"
+  if RUBY_VERSION < "2.4"
     gem "simplecov", "< 0.11.0", require: false
+  elsif RUBY_VERSION < "2.5.0"
+    gem "simplecov", "< 0.21.0", require: false
   else
     gem "simplecov", require: false
   end
+
 end

docker-compose-github.yml

@@ -3,5 +3,6 @@ services:
   netsnmp:
     environment:
       - BUNDLE_PATH=/usr/local/bundle
+      - BUNDLE_WITHOUT=development
     volumes:
       - "./vendor/bundle:/usr/local/bundle"

spec/support/specs.sh

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 RUBY_ENGINE=`ruby -e 'puts RUBY_ENGINE'`
 
 if [[ "$RUBY_ENGINE" = "truffleruby" ]]; then
@@ -11,8 +13,11 @@ else
   apk --update add g++ make git net-snmp-libs
 fi
 
+gem install bundler -v="1.17.3" --no-doc --conservative
 cd /home
-bundle install --quiet
+
+bundle -v
+bundle install
 
 if [[ ${RUBY_VERSION:0:1} = "3" ]]; then
   export RUBYOPT='-rbundler/setup -rrbs/test/setup'