"No ns form found ..." when using boot-reload

[pandeiro]

A very rare (maybe 5% or less of the time) bug I am hitting when using boot-cljs, boot-reload and multiple cljs.edn builds is the "No ns form found ...". It appears that the file that boot-reload is injecting prior to cljs compilation is empty when the (cljs ...) task tries to compile it:

Adding :require adzerk.boot-reload to main.cljs.edn...
Compiling ClojureScript...
? main.js
? tests.js
java.util.concurrent.ExecutionException: clojure.lang.ExceptionInfo: failed compiling file:/.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs {:file #object[java.io.File 0x48a25888 "/.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs"]}
             clojure.lang.ExceptionInfo: failed compiling file:/.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs
    data: {#object[clojure.lang.Keyword 0x2df8c34f ":file"] #object[java.io.File 0x48a25888 "/.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs"]}
             clojure.lang.ExceptionInfo: No ns form found in file:/.boot/cache/tmp/app/1/7o2s6s/adzerk/boot_reload.cljs at line 1 /.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs
    data: {#object[clojure.lang.Keyword 0x2df8c34f ":file"] "/.boot/cache/tmp/app/1/-hru27v/boot/cljs/main12754.cljs", #object[clojure.lang.Keyword 0x26a0e21e ":line"] 1, #object[clojure.lang.Keyword 0x5164ac91 ":column"] 1, #object[clojure.lang.Keyword 0x43da0d0f ":tag"] #object[clojure.lang.Keyword 0x25b13eda ":cljs/analysis-error"]}
               java.lang.AssertionError: No ns form found in file:/.boot/cache/tmp/app/1/7o2s6s/adzerk/boot_reload.cljs
                             cljs.analyzer$parse_ns$fn__2136.invoke  analyzer.cljc: 2706
                                      cljs.analyzer$parse_ns.invoke  analyzer.cljc: 2660
                                      cljs.analyzer$parse_ns.invoke  analyzer.cljc: 2651
                      cljs.analyzer$macro_autoload_ns_QMARK_.invoke  analyzer.cljc: 1782
cljs.analyzer$desugar_ns_specs$to_macro_specs__1835$fn__1838.invoke  analyzer.cljc: 1817
                                             clojure.core/filter/fn       core.clj: 2686
                                                                ...                     
                                                   clojure.core/seq       core.clj:  137
                                                clojure.core/map/fn       core.clj: 2616
                                                                ...                     
                                                   clojure.core/seq       core.clj:  137
                              cljs.analyzer$desugar_ns_specs.invoke  analyzer.cljc: 1825
                             cljs.analyzer$eval1863$fn__1865.invoke  analyzer.cljc: 1874
                                                                ...                     
                             cljs.analyzer$analyze_seq_STAR_.invoke  analyzer.cljc: 2368
                        cljs.analyzer$analyze_seq_STAR__wrap.invoke  analyzer.cljc: 2373
                                   cljs.analyzer$analyze_seq.invoke  analyzer.cljc: 2394
                                  cljs.analyzer$analyze_form.invoke  analyzer.cljc: 2503
                                 cljs.analyzer$analyze_STAR_.invoke  analyzer.cljc: 2550
                                       cljs.analyzer$analyze.invoke  analyzer.cljc: 2566
                   cljs.compiler$compile_file_STAR_$fn__3342.invoke  compiler.cljc: 1125
                                cljs.compiler$with_core_cljs.invoke  compiler.cljc: 1053
                            cljs.compiler$compile_file_STAR_.invoke  compiler.cljc: 1076
                         cljs.compiler$compile_file$fn__3383.invoke  compiler.cljc: 1237
                                  cljs.compiler$compile_file.invoke  compiler.cljc: 1216
                                  cljs.compiler$compile_root.invoke  compiler.cljc: 1291
                                           cljs.closure/compile-dir    closure.clj:  438
                                           cljs.closure/eval3772/fn    closure.clj:  478
                                         cljs.closure/eval3724/fn/G    closure.clj:  383
                                           cljs.closure/eval3785/fn    closure.clj:  492
                                         cljs.closure/eval3724/fn/G    closure.clj:  383
                          cljs.build.api/inputs/reify/compile-input        api.clj:  182
                                                clojure.core/map/fn       core.clj: 2624
                                                                ...                     
                                                   clojure.core/seq       core.clj:  137
                                                 clojure.core/apply       core.clj:  630
                                                clojure.core/mapcat       core.clj: 2660
                                                                ...                     
                               cljs.build.api/inputs/reify/-compile        api.clj:  186
                                                 cljs.closure/build    closure.clj: 1671
                                               cljs.build.api/build        api.clj:  219
                              adzerk.boot-cljs.impl/compile-cljs/fn       impl.clj:   63
                                 adzerk.boot-cljs.impl/compile-cljs       impl.clj:   62
                                                                ...                     
                                                 clojure.core/apply       core.clj:  630
                                              boot.pod/eval-fn-call        pod.clj:  184
                                                  boot.pod/call-in*        pod.clj:  191
                                                                ...                     
                                                  boot.pod/call-in*        pod.clj:  194
                                           adzerk.boot-cljs/compile  boot_cljs.clj:   75
                                      adzerk.boot-cljs/compile-1/fn  boot_cljs.clj:  138
                                clojure.core/binding-conveyor-fn/fn       core.clj: 1916

Could this be related to some race condition with the cljs task? The low reproducibility suggests something like that to me, prior to going into the impl.cljs and inspecting.

[Deraen]

Need more info. I have not seen this.

[Deraen]

@pandeiro Are you still seeing this? I'm going to close this if there's no more info.

[wagjo]

I'm seeing it too. Exception is:

java.lang.AssertionError: No ns form found in file:/home/wagjo/.boot/cache/tmp/home/proj/p3q/-x24pa9/adzerk/boot_cljs_repl.cljs
          cljs.analyzer$parse_ns$fn__2009.invoke  analyzer.cljc: 2751
             cljs.analyzer$parse_ns.invokeStatic  analyzer.cljc: 2706
                   cljs.analyzer$parse_ns.invoke  analyzer.cljc: 2687
             cljs.analyzer$parse_ns.invokeStatic  analyzer.cljc: 2697
cljs.closure/find-cljs-dependencies/invokeStatic    closure.clj:  691
cljs.closure/add-dependency-sources/invokeStatic    closure.clj:  749
                 cljs.closure/build/invokeStatic    closure.clj: 1892
               cljs.build.api/build/invokeStatic        api.clj:  206
 adzerk.boot-cljs.impl/compile-cljs/invokeStatic       impl.clj:   76
              adzerk.boot-cljs.impl/compile-cljs       impl.clj:   66
                                             ...                     
                 clojure.core/apply/invokeStatic       core.clj:  646
                              clojure.core/apply       core.clj:  641
                           boot.pod/eval-fn-call        pod.clj:  294
                               boot.pod/call-in*        pod.clj:  315
                                             ...                     
                               boot.pod/call-in*        pod.clj:  318
                        adzerk.boot-cljs/compile  boot_cljs.clj:   71
                   adzerk.boot-cljs/compile-1/fn  boot_cljs.clj:  126
             clojure.core/binding-conveyor-fn/fn       core.clj: 1916

Dependencies

   [adzerk/boot-cljs "1.7.228-1" :scope "test"]
   [adzerk/boot-cljs-repl "0.3.0" :scope "test"]
   [adzerk/boot-reload "0.4.4" :scope "test"]

task we're running

  (comp
   (system :sys #'foo.standalone/system :auto-start true)
   (watch)
   (less :source-map true :compression false :inline-javascript true)
   (reload :on-jsload 'foo.app/fig-reload)
   (cljs-repl)
   (cljs :source-map true))

[pandeiro]

@Deraen This issue still exists for us; its infrequency means it's not a big deal, but we still get failed tests now and then because of it. And now it has been seen by @wagjo as well. Not sure what should / can be done, but if there's something else I can do, please let me know.

[Deraen]

I'm yet to see this myself.

A start would be to have a test project where you can reproduce this so that I could try to reproduce this.

[pandeiro]

@wagjo Are you able to reproduce this reliably? How frequently do you see this? It would be great if we could create a sample repo for Juho to look at.

[wagjo]

Nope, I only get this error in about 5% of runs.

[mjmeintjes]

I think I might be getting the same bug - on Travis CI sometimes the build fails after successful run, even if nothing changed. E.g. https://travis-ci.org/mjmeintjes/boot-react-native/builds/109811514 vs https://travis-ci.org/mjmeintjes/boot-react-native/builds/109810642 (same source code, just merged branch).

[Deraen]

I think there is a chance that recent change in Boot-reload 0.5.0 might have fixed this: adzerk-oss/boot-reload@9f430b2

[Deraen]

I have not seen this myself in 5 months and I don't recall anyone at work mentioning this since the change, so I'll presume this was fixed.

[Deraen]

Except Boot-cljs-repl still uses the old way to inject code to the build: https://github.com/adzerk-oss/boot-cljs-repl/blob/master/src/adzerk/boot_cljs_repl.clj#L168