ExecJS can't find JavaScriptCore in macOS 10.15 (Catalina)

[paulmakepeace]

[execjs-catalina]$ gem install execjs
Successfully installed execjs-2.7.0
1 gem installed
[execjs-catalina]$ irb -rexecjs
Traceback (most recent call last):
...
/Users/makepeace/.rbenv/versions/2.7.0/lib/ruby/gems/2.7.0/gems/execjs-2.7.0/lib/execjs/runtimes.rb:58:in `autodetect': Could not find a JavaScript runtime. See https://github.com/rails/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
[execjs-catalina]$ sw_vers -productVersion
10.15.4

runtimes.rb:30 is looking in

/System/Library/Frameworks/JavaScriptCore.framework/Versions/A/Resources/jsc

...but it's now in,

/System/Library/Frameworks/JavaScriptCore.framework/Versions/A/Helpers/jsc

Bonus: use Current instead of A:

$ ls -l /System/Library/Frameworks/JavaScriptCore.framework/Versions/Current
lrwxr-xr-x  [...] /System/Library/Frameworks/JavaScriptCore.framework/Versions/Current -> A

[stonefield]

+1

[tedgarb]

+1

[shantamg]

+1
After updating, my local server won't start. Rather than try to symlink jsc I have decided to install node.js and that's fine with me, but this certainly should be fixed.

[jungbunzlav]

+1

[zz5678]

macOS 10.15, same error from python module PyExecJS:

raise ValueError('Can not find the given interpreter: %r' % interpreter)
ValueError: Can not find the given interpreter: 
'/System/Library/Frameworks/JavaScriptCore.framework/Versions/A/Resources/jsc'

[byroot]

Fixed in #98