Hi,

While compiling using cljsbuild I get the error below. How do I trace it
back to the source file that caused this error ?

Thanks,
Murtaza

Compiling "resources/public/cljs/client.js" failed:
Exception in thread "main" java.util.concurrent.ExecutionException:
java.lang.NullPointerException
    at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:252)
    at java.util.concurrent.FutureTask.get(FutureTask.java:111)
    at clojure.core$future_call$reify__6110.deref(core.clj:6156)
    at clojure.core$deref.invoke(core.clj:2080)
    at clojure.core$map$fn__4087.invoke(core.clj:2434)
    at clojure.lang.LazySeq.sval(LazySeq.java:42)
    at clojure.lang.LazySeq.seq(LazySeq.java:60)
    at clojure.lang.RT.seq(RT.java:473)
    at clojure.core$seq.invoke(core.clj:133)
    at clojure.core$dorun.invoke(core.clj:2725)
    at clojure.core$doall.invoke(core.clj:2741)
    at cljsbuild.util$in_threads.invoke(util.clj:31)
    at user$eval2364.invoke(NO_SOURCE_FILE:1)
    at clojure.lang.Compiler.eval(Compiler.java:6511)
    at clojure.lang.Compiler.eval(Compiler.java:6501)
    at clojure.lang.Compiler.eval(Compiler.java:6500)
    at clojure.lang.Compiler.eval(Compiler.java:6501)
    at clojure.lang.Compiler.eval(Compiler.java:6477)
    at clojure.core$eval.invoke(core.clj:2797)
    at clojure.main$eval_opt.invoke(main.clj:297)
    at clojure.main$initialize.invoke(main.clj:316)
    at clojure.main$null_opt.invoke(main.clj:349)
    at clojure.main$main.doInvoke(main.clj:427)
    at clojure.lang.RestFn.invoke(RestFn.java:421)
    at clojure.lang.Var.invoke(Var.java:419)
    at clojure.lang.AFn.applyToHelper(AFn.java:163)
    at clojure.lang.Var.applyTo(Var.java:532)
    at clojure.main.main(main.java:37)
Caused by: java.lang.NullPointerException
    at java.util.regex.Matcher.getTextLength(Matcher.java:1233)
    at java.util.regex.Matcher.reset(Matcher.java:308)
    at java.util.regex.Matcher.<init>(Matcher.java:228)
    at java.util.regex.Pattern.matcher(Pattern.java:1088)
    at clj_stacktrace.utils$re_gsub.invoke(utils.clj:6)
    at clj_stacktrace.core$clojure_ns.invoke(core.clj:14)
    at clj_stacktrace.core$parse_trace_elem.invoke(core.clj:68)
    at clojure.core$map$fn__4087.invoke(core.clj:2434)
    at clojure.lang.LazySeq.sval(LazySeq.java:42)
    at clojure.lang.LazySeq.seq(LazySeq.java:60)
    at clojure.lang.RT.seq(RT.java:473)
    at clojure.core$seq.invoke(core.clj:133)
    at clojure.core$map$fn__4087.invoke(core.clj:2426)
    at clojure.lang.LazySeq.sval(LazySeq.java:42)
    at clojure.lang.LazySeq.seq(LazySeq.java:60)
    at clojure.lang.RT.seq(RT.java:473)
    at clojure.core$seq.invoke(core.clj:133)
    at clojure.core$map$fn__4087.invoke(core.clj:2426)
    at clojure.lang.LazySeq.sval(LazySeq.java:42)
    at clojure.lang.LazySeq.seq(LazySeq.java:60)
    at clojure.lang.Cons.next(Cons.java:39)
    at clojure.lang.RT.length(RT.java:1625)
    at clojure.lang.RT.seqToArray(RT.java:1566)
    at clojure.lang.LazySeq.toArray(LazySeq.java:140)
    at clojure.lang.RT.toArray(RT.java:1544)
    at clojure.core$to_array.invoke(core.clj:326)
    at clojure.core$sort.invoke(core.clj:2699)
    at clojure.core$sort.invoke(core.clj:2696)
    at clj_stacktrace.repl$find_source_width.invoke(repl.clj:98)
    at clj_stacktrace.repl$pst_on.invoke(repl.clj:107)
    at clj_stacktrace.repl$pst_PLUS_.doInvoke(repl.clj:129)
    at clojure.lang.RestFn.invoke(RestFn.java:408)
    at cljsbuild.compiler$compile_cljs.invoke(compiler.clj:71)
    at cljsbuild.compiler$run_compiler.invoke(compiler.clj:85)
    at user$eval2364$fn__2367.invoke(NO_SOURCE_FILE:1)
    at cljsbuild.util$in_threads$fn__2232$fn__2233.invoke(util.clj:31)
    at clojure.core$binding_conveyor_fn$fn__3989.invoke(core.clj:1819)
    at clojure.lang.AFn.call(AFn.java:18)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1 110)
    at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java: 603)
    at java.lang.Thread.run(Thread.java:722)

From the stacktrace and some source reading, it seems clj-stacktrace
passes null as class-name in clj-stacktrace.core/clojure-ns, which
passes it to a regex function.
That should not even be possible, because it passes the same value to
clj-stacktrace.core/clojure-code?, which would already throw, a few
lines before.
Also, the null value originates from StackTraceElement.getClassName()
which I'm not even sure is allowed to be null.

Maybe it was some funky state you got your JVM into. Can you reproduce
the error?

Also, are you running the latest version of clj-stacktrace?

Herwig thanks for your comments.

I was able to solve the problem by doing the following. I created a new
source directory and changed the src path for lein-cljsbuild to the new src
dir. Then I started saving one file after another to the dir. All this
while I had lein cljsbuild running as auto. The instance I saved the file
having faulty code to the new dir, the error stacktrace showed up in the
terminal running cljsbuild.

It did solve my problem, however is there a better way to do it then the
trial and error method ?

Thanks,
Murtaza