Update README.md

[sbuggay]

I had to run npm run prebuild to setup build.ninja in out/Default. Without it I wasn't able to run any of the other build options.

Summary

Following the readme, I was running into this error

ninja: Entering directory `/Users/devanb/github/rn-chrome-devtools-frontend__workspace/rn-chrome-devtools-frontend/out/Default'
ninja: error: loading 'build.ninja': No such file or directory

After running prebuild, out/Default was setup correctly. Adding that step to the readme.

Test plan

Fresh clone

source setup.sh
npm run prebuild
npm run build

• This change maintains backwards compatibility with previous Local Storage data (if modifying settings, experiments, or other persisted client state).

Upstreaming plan

• This commit should be sent as a patch to the upstream devtools-frontend repo. I've reviewed the contribution guide.
• This commit is React Native-specific and cannot be upstreamed.

[hoxyq]

prebuild should always run before build command, unless user has ignore-scripts setting disabled in their npm config.

These are called hooks and they can run before or after the script, depending on the prefix: pre or post. I am not opposed to adding this to our README, though.

Can you run npm config list -l and check what is the value of ignore-scripts setting? If it is true, then hooks won't be executed by default.

[vzaidman]

@hoxyq

I had the same issue when I recently installed the repo as well. I had to spent time figuring the same thing out. I propose merging this change.

I've just noticed that for the last 10 months, ignoring scripts is true for everyone. See https://github.com/facebook/react-native-devtools-frontend/blob/main/.npmrc

npm config list -l

shows

; "project" config from /Users/vzaidman/projects/rn-chrome-devtools-frontend__workspace/rn-chrome-devtools-frontend/.npmrc

ignore-scripts = true
include = []
omit = ["optional"]
package-lock = true
prefer-online = true
registry = "https://npm.skia.org/chrome-devtools"
save-dev = true
save-exact = true
save-prefix = ""

; "cli" config from command line options

long = true