I'm trying to concatenate some JS files and create an index source map  for that generated file with links to the source maps of the files instead of including the source map directly. That however does not seem to work as expected (or I am doing it wrong).
Here is what I have:
in the console I get a message of "hello world" at "app.js:41594", which should be a link to the source mapped file "app.cljs:3".
"Cannot read property 'sources' of undefined" at inspector.js:6556
which either means my source map is incorrect or devtools doesn't support it. I do not quite know how to debug this any further. I think the source map is correct and if I manually follow all the urls they all download correctly. Chrome however never attempts to get  which the index map refers to.
The not-concatenated file  works correctly and logs with the expected source location of "app.cljs:3".
So the question is
a) is my source map correct?
b) are index source maps with url even supported?
Thoughts? It is kinda hard to google this topic ...