Confusing error when paths fed to builder are empty

[zampino]

This is thrown

Execution error (NullPointerException) at nextjournal.clerk.builder/build-static-app! (builder.clj:284).
Cannot invoke "clojure.lang.IFn.invoke(Object)" because "report_fn" is null

when calling (builder/build-static-app! {:paths ["foo/**/*.clj"]}) against an empty glob "foo/**/*.clj", also reproducible with (builder/build-static-app! {:paths []}).

[ghost]

Possibly related: if I pass :paths with a single path — if the options map contains only :paths that works more or less fine. But if I also specify :index then I get the same NPE.

As discussed in Clojurians

[kautsig]

Can reproduce the problem @aviflat described in :mvn/version "0.12.707". If I understand the code correctly, the problem is that the build-static-app! function, which extracts :keys and then calls process-build-opts which sets the :report-fn.

(let [{:as opts :keys [download-cache-fn upload-cache-fn report-fn compile-css? expanded-paths error]}
        (try (process-build-opts (assoc opts :expand-paths? true))
             (catch Exception e
               {:error e}))

I am not sure how empty paths fix relate to this though.

[kautsig]

My previous comment is wrong. I failed to read the let binding correctly. I am still investigating the NPE.

[kautsig]

Ok, I got it.

process-build-opts threw an error, never setting report-fn at all. Root cause was:

`:index` must be string and point to existing file`.

No reason to reopen that, sorry for the noise.