Update gem to 2.7.9 (protocolbuffers#6265)

New bundler doesn't work with old gem: rbenv/rbenv#1138
gminor7 · Jun 17, 2019 · 444354f · 444354f
1 parent 310ba5e
commit 444354f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/kokoro/linux/dockerfile/release/ruby_rake_compiler/Dockerfile b/kokoro/linux/dockerfile/release/ruby_rake_compiler/Dockerfile
@@ -1,3 +1,3 @@
 FROM grpctesting/rake-compiler-dock_53c22085d091183c528303791e7771359f699bcf
 
-RUN /bin/bash -l -c "gem install bundler"
+RUN /bin/bash -l -c "gem update --system '2.7.9' && gem install bundler"