NullPointerException on 'lean new re-frame foo'

[day8]

NullPointerException on 'lean new re-frame foo'

[gadfly361]

@dgr Can you run lein -v and copy here what you see?

I am unable to reproduce this issue.

~/gadfly/temp$ lein -v
Leiningen 2.7.1 on Java 1.8.0_121 OpenJDK 64-Bit Server VM
~/gadfly/temp$ rm -rf ~/.m2/repository/re-frame/
~/gadfly/temp$ lein new re-frame foo
Retrieving re-frame/lein-template/0.3.2/lein-template-0.3.2.pom from clojars
Retrieving re-frame/lein-template/0.3.2/lein-template-0.3.2.jar from clojars
Generating re-frame project.

[gadfly361]

@dgr Ping

Can you please try:

lein -v

rm -rf ~/.m2/repository/re-frame/

lein new re-frame foo

And copy the console log here

[dgr]

Sorry for the delay. Here is the output of lein -v:
Leiningen 2.8.1 on Java 1.8.0_45 Java HotSpot(TM) 64-Bit Server VM
This is on MacOS 10.13.2 (High Sierra), running leiningen installed via brew.

[dgr]

I tried removing the re-frame Maven info and it still didn't work:

Davids-MacBook-Pro:clojure dave$ rm -rf ~/.m2/repository/re-frame
Davids-MacBook-Pro:clojure dave$ lein new re-frame foo
java.lang.NullPointerException: null
 at clojure.core$apply.invokeStatic (core.clj:648)
    clojure.core$apply.invoke (core.clj:641)
    leiningen.new$create.invokeStatic (new.clj:81)
    leiningen.new$create.doInvoke (new.clj:57)
    clojure.lang.RestFn.invoke (RestFn.java:425)
    clojure.lang.AFn.applyToHelper (AFn.java:156)
    clojure.lang.RestFn.applyTo (RestFn.java:132)
    clojure.core$apply.invokeStatic (core.clj:650)
    clojure.core$apply.invoke (core.clj:641)
    leiningen.new$new.invokeStatic (new.clj:204)
    leiningen.new$new.doInvoke (new.clj:134)
    clojure.lang.RestFn.invoke (RestFn.java:439)
    clojure.lang.Var.invoke (Var.java:388)
    clojure.lang.AFn.applyToHelper (AFn.java:160)
    clojure.lang.Var.applyTo (Var.java:700)
    clojure.core$apply.invokeStatic (core.clj:648)
    clojure.core$apply.invoke (core.clj:641)
    leiningen.core.main$partial_task$fn__4667.doInvoke (main.clj:284)
    clojure.lang.RestFn.applyTo (RestFn.java:139)
    clojure.lang.AFunction$1.doInvoke (AFunction.java:29)
    clojure.lang.RestFn.applyTo (RestFn.java:137)
    clojure.core$apply.invokeStatic (core.clj:648)
    clojure.core$apply.invoke (core.clj:641)
    leiningen.core.main$apply_task.invokeStatic (main.clj:334)
    leiningen.core.main$apply_task.invoke (main.clj:320)
    leiningen.core.main$resolve_and_apply.invokeStatic (main.clj:340)
    leiningen.core.main$resolve_and_apply.invoke (main.clj:336)
    leiningen.core.main$_main$fn__4734.invoke (main.clj:420)
    leiningen.core.main$_main.invokeStatic (main.clj:411)
    leiningen.core.main$_main.doInvoke (main.clj:408)
    clojure.lang.RestFn.invoke (RestFn.java:436)
    clojure.lang.Var.invoke (Var.java:388)
    clojure.lang.AFn.applyToHelper (AFn.java:160)
    clojure.lang.Var.applyTo (Var.java:700)
    clojure.core$apply.invokeStatic (core.clj:646)
    clojure.main$main_opt.invokeStatic (main.clj:314)
    clojure.main$main_opt.invoke (main.clj:310)
    clojure.main$main.invokeStatic (main.clj:421)
    clojure.main$main.doInvoke (main.clj:384)
    clojure.lang.RestFn.invoke (RestFn.java:482)
    clojure.lang.Var.invoke (Var.java:401)
    clojure.lang.AFn.applyToHelper (AFn.java:171)
    clojure.lang.Var.applyTo (Var.java:700)
    clojure.main.main (main.java:37)
Davids-MacBook-Pro:clojure dave$

[dgr]

BTW, just some more info... I don't see lein trying to download any dependencies that might exist for the template. Typically, when I first use a template, it will download a large amount of stuff. I don't see that this time. Not sure if that's helpful or not.

[gadfly361]

@dgr That is helpful because if you were to successfully remove the most recent version of the re-frame template from your .m2 directory ... it should have to re-download it. For example:

~/gadfly/temp$ rm -rf ~/.m2/repository/re-frame/
~/gadfly/temp$ lein new re-frame foo
Retrieving re-frame/lein-template/0.3.3/lein-template-0.3.3.pom from clojars
Retrieving re-frame/lein-template/0.3.3/lein-template-0.3.3.jar from clojars
Generating re-frame project.

Looking at your log, I see this:

Davids-MacBook-Pro:clojure dave$ lein new re-frame foo
java.lang.NullPointerException: null

Which means either a) there is a null pointer exception before lein tries to re-download the re-frame-template to .m2 ... or b) your .m2 directory is located somewhere else and you never actually deleted the re-frame directory from .m2

Regarding a) ... does lein work in general? If you try lein new reagent foo does that work? (I am sure it likely does, but just trying to cover that base)

Regarding b) ... can you confirm the location of your .m2 directory? I am a linux user and don't recall where mac / brew would place that.

[dgr]

(a) Yes, lein works in general. No problems with any other template that I have found thus far. I did lein new reagent foo and it worked great.

(b) Here's where .m2 is located:

Davids-MacBook-Pro:clojure dave$ cd ~/.m2
Davids-MacBook-Pro:.m2 dave$ pwd
/Users/dave/.m2

[dgr]

OK, I just sort of solved it. At least I got it to work now, but I'm not sure why this would be throwing it off. I started poking around in my ~/.lein/profiles.clj and found {:user {:plugins [[luminus/lein-template "2.9.10.95"]]}} in there for some reason. I commented out that template and re-ran lein new re-frame foo and it correctly downloaded the re-frame template from clojars and did its thing.

Now, the question is, why would that be the case? Why did the other templates work just fine while re-frame did not? I think I was reading a book about Luminus at one point and it had me put that into my profiles.clj, for what reason, I don't know (maybe to lock the luminus version to the specific one used in the book??).

I have no idea how the lein template system works, but I suspect that it's dynamically dispatching to the template code based on some sort of name and that Luminus probably had some sort of name clash with whatever re-frame was trying to do. But I don't really know what I'm talking about, so that could be totally wrong, too.

Anyway, the immediate problem is resolved and it was my environment at fault. We can probably close this issue, although it might be worth it to understand what was happening to at least document it if somebody ever bumps into it again.