A while back I wanted to experiment with a more recent version of React in a few projects. Specifically I wanted to enable some of the feature flags that the React team uses to gate specific experiemnts. These flags are compile-time evaluated, meaning I can't simply change them at runtime and have any version of React installed reflect the changes. Instead, I needed to clone the repo, change the flags, and then run a build locally.
Now, the React repo may have changed since I last tried this (which was maybe 4 years ago now), but back then you needed to have Java setup locally (or at least JDK setup) in order to complete the builds. At the time this was a decent hurdle to overcome, since I was mostly used to more common build toolchains like Babel/Webpack/etc.
Since then, I've discovered this amazing resource that someone made that hosts build assets for different PRs, commits, or versions of the packages generated from the repo. This is the react-builds site.
The really neat thing about this site is that you can download any build artifact for any commit within the repo (as far as I understand it, I'm sure you probably can't go all the way back to the first commit and download those builds).
In addition, you can also use this to download and vendor packages that haven't
been published yet (👀 looking at you react-server-dom-esm 👀).
I was trying to find this resource the other day so I figured I'd blog a bit about it as a form of long term memory 😂.