Having just gone through this, I'm happy to work with whomever wants to pick this up to share knowledge. Don't really mind doing this myself either.
@rsimha @alabiaga Any interest?
Happy to work on this.
We can also split it up. 馃槃 There's about a year of updates left.
CC releases ~monthly. I'd recommend making each upgrade PR as small as possible to minimize risk.
@choumx Was there a sweet spot you managed to identify when you initially attempted an upgrade to the latest version?
I'd try the smallest upgrade possible first. https://github.com/google/closure-compiler/wiki/Binary-Downloads
This issue hasn't been updated in awhile. @rsimha Do you have any updates?
We're currently at the latest version of closure. Closing this in favor of #22452, which tracks the effort to dynamically generate runner.jar, so we can always be at the latest version.
This is now truly done, and future updates should be automatic (modulo breaking changes). See https://github.com/ampproject/amphtml/pull/23759#issuecomment-520162085
One more success in the series: #24096