Could not create task or type of type: junit. — or the worst error message ever

Currently, I have to work a lot with ant for class, and generally, I like it.

The XML format used to describe the build tasks is pretty straightforward, makes sense most of the time and is even pretty extensible, so that things like JUnit testing are as easy as the ABC. Well — they should be.

When using ant with Eclipse, everything worked fine. But then, when I checked out the project on the command line and confidently ran an “ant test”, I was presented with the following error message, which through its length alone has such a beauty that I should truly consider printing it out and put it on my wall to admire it daily.

BUILD FAILED
/blah…/build.xml:51:
Could not create task or type of type: junit.

Ant could not find the task or a class this task relies upon.

This is common and has a number of causes; the usual
solutions are to read the manual pages then download and
install needed JAR files, or fix the build file:

- You have misspelt 'junit'.
Fix: check your spelling.

- The task needs an external JAR file to execute
and this is not found at the right place in the classpath.
Fix: check the documentation for dependencies.
Fix: declare the task.

- The task is an Ant optional task and the JAR file and/or libraries
implementing the functionality were not found at the time you
yourself built your installation of Ant from the Ant sources.
Fix: Look in the ANT_HOME/lib for the ‘ant-’ JAR corresponding to the
task and make sure it contains more than merely a META-INF/MANIFEST.MF.
If all it contains is the manifest, then rebuild Ant with the needed
libraries present in ${ant.home}/lib/optional/ , or alternatively,
download a pre-built release version from apache.org

- The build file was written for a later version of Ant
Fix: upgrade to at least the latest release version of Ant

- The task is not an Ant core or optional task
and needs to be declared using <taskdef>.

- You are attempting to use a task defined using
<presetdef> or <macrodef> but have spelt wrong or not
defined it at the point of use

Remember that for JAR files to be visible to Ant tasks implemented
in ANT_HOME/lib, the files must be in the same directory or on the
classpath

Please neither file bug reports on this problem, nor email the
Ant mailing lists, until all of these causes have been explored,
as this is not an Ant bug.


This is not an ant bug? Oh yes it is. “ant-junit.jar” is now shipped by default with ant and still, ant claims not to know about that task?

And anyway – why couldn’t the developer who took the time to write such a cryptic error message use his effort instead to fix the bug?!

Unbelievable enough – however, since others did a much better job on ranting about ant’s worst error message ever, I’m going to stop now and provide a solution for that problem instead (since ant developers obviously didn’t feel alike):

Go to $ANT_HOME/lib and make a symbolic link to your JUnit’s junit.jar file. The directories differ for most operating systems, but the system is the same: Ant apparently does not find JUnit in its classpath, resulting in the error message above. When JUnit is linked to Ant’s library dir however, it can find JUnit and will call the unit tests as expected.

(Now it took me like 4 lines to describe a fix for the problem. Why such an easy fix is not part of the ant error message will probably remain a secret forever.)

I hope I helped some of you guys who have the same problem. Keep having fun programming!



March 4th, 2006

Permalink | 42 Comments

Categories: OSU OSL Crosspost, Tech Talk

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42 Responses to “Could not create task or type of type: junit. — or the worst error message ever”

  1. Thank you :)

    1 Thank you :) on March 12th, 2006 at 6:21 am

  2. You’re welcome :) — I knew there were people who could use the solution…

    2 Fred on March 12th, 2006 at 11:23 am

  3. I just spent a half hour trying to understand what all the ANT documentation was saying. Then I gave up and found your page. Woohoo!

    3 Rob on March 13th, 2006 at 10:31 am

  4. Just one note… The following doesn’t seem to work sometimes in Cygwin:
    (from $ANT_HOME/lib)
    ln -s $JUNIT_HOME/junit.jar .

    It creates a symlink, but either symlinks aren’t perfect in some installations of Cygwin, or ant just doesn’t like them.

    I ended up copying the junit.jar

    4 Jeremy Young on March 16th, 2006 at 5:26 pm

  5. Ah, thanks. That’s interesting, too. By the way, is there any reason to use ant on cygwin and not the real Windows port of it?

    5 Fred on March 17th, 2006 at 12:09 am

  6. I don’t know. I just never really felt like the Windows command prompt was a valid development environment. :) If I’m going to use command line, I figured I’d use a real one, or at least one that immitated a real one better. I just love the commands that are available….. It seems that cygwin is the best and quickest source for all the great tools to be used on a Windows box.

    I’m too much of a gamer to switch totally away from Windows, and too poor to have a separate development box at home.

    6 Jeremy Young on March 21st, 2006 at 9:22 am

  7. That’s a phantastic job you have done.
    This helps for most of the people who are working with ant to run their test cases.

    7 Surya on March 24th, 2006 at 11:13 pm

  8. Thanks!

    8 err on March 26th, 2006 at 12:21 pm

  9. You are a lifesave – I was definitely reching the point of madness for that one!

    9 TimRyanNZ on March 30th, 2006 at 9:00 pm

  10. Not much of a solution. If I upgrade ant (which I do using symbolic links in linux) the above won’t work for the upgrade. One alternative from the (crappy) ant documentation is:

    $ export CLASSPATH=$CLASSPATH:$PATHTO/junit.jar
    $ ant unitTests

    which I put into my cron job.

    10 John Hoffman on April 3rd, 2006 at 4:28 am

  11. Interesting. However, it’s not exactly cleaner to put a classpath export into a cron job than symlinking a JAR file…

    Maybe you should use $HOME/.bashrc or similar instead.

    11 Fred on April 3rd, 2006 at 6:38 am

  12. […] i podobne nad których treÅ›ciÄ… wypowiedziaÅ‚o siÄ™ sporo internautów. […]

    12 Ant i Junit at punkracy.com | eJournal on April 23rd, 2006 at 10:34 am

  13. it helps, thanks.

    13 chi on May 4th, 2006 at 11:25 am

  14. Thank you Fred, for the solution. I had a bunch of files that came with an ant build.xml file that I wanted to use in Eclipse. After creating the project "from an existing ant build file", I had some trouble getting the junit ant task to work.

    IMO the better solution is to put junit.jar in one’s classpath rather than making links.

    To get the tests to run in eclipse I also needed to add junit.jar in the classpath for build.xml (in the run configuration for build.xml). Oddly, adding junit.jar in the classpath for the junit task didn’t work.

    14 Raghav Karol on May 9th, 2006 at 3:05 am

  15. It is not an ant bug. you simply forgot to use ant -lib C:\PATH\TO\YOUR\junit.jar

    15 Dude on May 16th, 2006 at 1:09 am

  16. supporting junit tasks but not importing the JAR file without special options is in fact a bug, sorry ;) YMMV of course but if me and the other 50000 people who have that problem consider it a bug, shouting "it’s a feature" is not quite convincing…

    16 Fred on May 17th, 2006 at 9:19 am

  17. Tnx alot!

    17 Vinicius Rocha on July 7th, 2006 at 1:17 pm

  18. I had similar problem, but mine happened when using ANT plugin in eclipse. It can’t see the junit jar. I tried adding the junit.jar in eclipse/plugin/ /lib (which is the default ANT home) but it still can’t detect it. So i just explicitly add the junit.jar in the classpath of the ant build.

    thanks!

    18 jenny on July 19th, 2006 at 6:20 pm

  19. Thank you Raghav – that tip about putting the junit.jar in the classpath of the build.xml is spot on. I tried for ages, putting the jar in the %ANT_HOME%/lib directory and using the classpath element in Ant. But you gave me the good solution.

    Thanks!

    19 Graeme on July 24th, 2006 at 12:26 pm

  20. Seems like the nested element inside can not be used for the junit.jar to be used by ANT as suggested in the build.xml that comes with the CruiseControl ConnectFour sample..

    20 Guille on August 14th, 2006 at 2:33 pm

  21. when i run any test on command prompt for junit, it give me the error “Exception in thread main “NoClassDefFound” Exception.
    even though i have set the classpath through Envirenment varibles.
    Plz tell me where is the problem.

    21 upendra on August 18th, 2006 at 7:51 am

  22. You are a great person! Wow! I was becoming demonically obsessed with fixing this problem, and you saved my whole week. Thanx so much for putting this out there!!

    22 Mark Gross on August 31st, 2006 at 7:35 am

  23. Thanks man! I spent more than a day trying to figure out what the problem was. This page came into my way as an angle.

    23 Sunil on September 5th, 2006 at 4:38 am

  24. The creation of the link solved my problem. thanks

    24 Mohit Gupta on November 23rd, 2006 at 10:06 pm

  25. too bad even the recommended solution sucks. if some of your projects use junit 3.8 and some use junit 4.2, putting junit in ant’s distribution directory tree isn’t going to end your troubles.

    25 barney on December 1st, 2006 at 7:54 am

  26. Hi,

    Thanks for the hints. This *almost* got me there. In my particular case (debian, sun jdk, when building cruisecontrol) I actually needed to have ant-junit.jar (vs. junit.jar, which was already there) present in a classpath directory.

    26 Andre on December 14th, 2006 at 4:27 am

  27. Thanks a lot!

    27 Jerry Debidien on March 12th, 2007 at 6:08 am

  28. I am trying to do an ant build with junit within a Windows command line.

    Here is the junit portion of the build.xml:

    Now this build.xml file performs an ant build with:

    > ant -lib ..\lib\junit\jar\junit-4.3.1.jar

    However, it returns the error “Could not create task or type of type: junit” if the -lib entry is not provided.

    What is wrong with my build.xml file junit entry?

    28 jeff_seattle on May 30th, 2007 at 12:05 pm

  29. The last submission did not allow me to past in xml.

    Here is the junit portion of the build.xml:

    target name=”test-server” depends=”compile-server” description=”unit test server”
    junit
    printsummary=”yes”
    haltonfailure=”yes”
    classpath
    pathelement location=”${server.build.location}”
    pathelement location=”..\lib\junit\jar\junit-4.3.1.jar”
    /classpath
    formatter type=”brief” usefile=”true” /
    batchtest todir=”${junit.results}”
    fileset dir=”${server.build.location}”
    include name=”**/*Test.class” /
    /fileset
    /batchtest
    /junit
    /target

    29 jeff_seattle on May 30th, 2007 at 12:09 pm

  30. Thanks for the solution.. it helps me a lot..!

    30 Niranjan on June 11th, 2007 at 8:47 pm

  31. Thanks a lot!
    that solved my problem :)

    31 Hafeth on June 25th, 2007 at 6:13 am

  32. THANKS!

    32 Rik on November 21st, 2007 at 1:50 am

  33. Thanks!

    33 mmm on December 13th, 2007 at 2:01 am

  34. after typing the above solution, i get a different error
    “No tests found in com.iTest.apps.SampleTest”

    Any help is highly appreciated

    34 suresh on February 15th, 2008 at 2:20 pm

  35. i had to copy junit-*.jar file to the ANT_HOME\lib for it to work..njoi..

    35 frozen84 on April 11th, 2008 at 3:24 am

  36. This bugfix doesn’t work for me…

    I still get the same error after creating a symbolic link or even after copying the file to ANT_HOME/lib…

    Even the suggested solution at Ants-FAQ doesn’t help more… extracting ant-junit.jar from the ANT_HOME/lib and using a own taskdef with junit.jar and ant-junit.jar in the same doesn’t work.

    36 Flexi on May 27th, 2008 at 12:49 am

  37. trying!!!

    37 tr on July 3rd, 2008 at 1:52 am

  38. If you run the ant in eclipse , please go to windows -> preferences -> Ant -> Runtime -> Classpath, then click the Ant Home Entries, hit the Add JARs, select the Junit.jar. okey, you can run the ant without boresome error message.

    38 Jaster on October 15th, 2008 at 1:33 am

  39. THX A LOT!!! It worked perfectly :)

    39 Luca on October 16th, 2008 at 9:26 am

  40. I found that using the -lib option to refer to the directory where your junit.jar resides also works.

    40 Thaddeus on May 30th, 2009 at 12:44 am

  41. In debian you can install “ant-optional” package to solve this.

    41 Sniff on July 16th, 2009 at 2:35 pm

  42. #yum install ant-junit does the job on RH distribution also.

    42 veraz01170 on July 22nd, 2009 at 3:09 pm

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