Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.


Next, create a new branch for yourself:

Code Block
$ git checkout -b fixbug42
Switched to a new branch "fixbug42"

Now you're ready to get hacking. Make sure relevant doc strings are up to date and that all existing regression tests still pass e.g. for clojure core run:

Code Block
# is a bash shell script, which is unlikely to work on Windows unless you have bash installed somehow
$ ./             # Only needed once in a new Clojure tree, for ant to work
$ ant

# Some prefer to use Maven rather than ant
$ mvn clean test

As noted in readme.txt, you will need to run ./ as a one-time setup before running ant.  If you want to add new tests, that would be great too. Once you've finished making your changes you need to commit them. Please use a commit message that begins with the JIRA number (CLJ-xyz)!

Code Block
$ git commit -a -m "CLJ-932 fixed annoying bug, refs #42"
Created commit 8f7c712: fixed annoying bug, refs #42
1 files changed, 0 insertions(+), 1 deletions(-)


Code Block
$ git format-patch master --stdout -U15 > your-patch-file.diffpatch

Adding Patchespatches

Now you can attach that patch file to the JIRA ticket.  In the More Actions menu near the top of the page, select Attach Files.  Please read and follow the recommendations below when writing comments about your attached patch.  Screeners have limited time available for screening.  You are more likely to get your patch approved if you can be as clear as you can, and as efficient with their time as possible.

  • Please use .diff or .patch (not .txt) as a suffix for patch files.
  • Read your patch file before attaching it.  If you see things like white space changes unrelated to the portion of code you are modifying, please edit and remove those changes and create another patch.  Also, while it is nice when developing to do multiple commits in a sequence, with explanations of each commit, patch reviewers usually prefer to have all changes in one commit in the submitted patch.
  • Using 'git add --patch' to stage your changes will make it easier to avoid committing extraneous changes.
  • Please use a name different from all existing attachments on the ticket.  JIRA allows you to add multiple attachments with the same name, but later ones do not replace earlier ones.  This can lead to confusion when referring to patches by name.
  • Include the file name and date of the patch in any comments referring to it.  It is possible to match up comments with patches based on the date and time, but it is tedious and error prone.
  • To get email whenever the ticket is updated, click on the word "Watch" in the top right area of the page.  This can help you know when someone else comments on your patch, or creates a new one, etc.  Click "Watching" if you want to stop these update emails for that ticket.  You may want to verify that the automated emails get through your spam filter.  Emails will be sent to the address associated with your JIRA account, and will come from the address 
  • If you create a new patch that incorporates one or more earlier ones, please combine them all into one patch file, and indicate in your comments that you have done this (with file names and dates of the patches you are superseding). One exception to this is when there are significant largely independent contributions from multiple people (for example, one made a code change and the other wrote the tests) and both want credit. In that case, a single patch file with multiple commits is fine. However, we'd like to avoid multiple patches that repeatedly modify the same code.
  • If one of your patches becomes superseded by a later one, consider removing your patch to avoid confusion.  See the instructions under the heading "Removing Patches" below.


A stale patch means one that used to apply cleanly to the latest Clojure master version, but due to commits made since the patch was created, it no longer does.  In particular, the output of this command:

Code Block
%$ git am --keep-cr -s --ignore-whitespace < patch_file.patch

includes 'Patch failed' and 'To restore the original branch and stop patching, run "git am --abort"'.  You should do the "git am --abort" to get rid of state of the failed patch attempt left behind by the command above.

"git am" is very "fragile", meaning that if the patch_file was created with one version of the source code, all it takes for the command to fail is a change in any of the lines of context present in the patch file, even if it is not one of the lines being changed by the patch.  This is especially common for files containing unit tests, because people usually add new tests at the end of such a file, and so the lines of context before the new test change if two different patches add a new test to the end of the same file.

To apply such a patch, the 'patch' program by Larry Wall is extremely useful.  It comes preinstalled with Mac OS X and most Linux distributions.  You can easily install it with Cygwin for Windows.use the --reject flag:

Code Block
%$ patchgit apply -p1-reject < patch_file.patch

The output will give you some hints of whether each "hunk" of the patch file succeeded or failed.  If they all succeed, then likely the only thing wrong with the patch file is that a few context lines were changed.  If any hunks fail, patch creates files ending with ".rej" containing rejected hunks that it did not apply, and you can focus on those as places where the source code likely changed more significantly.  A command like this will find them all:

Code Block
%$ find . -name '*.rej'

You will need to look at those rejected hunks, perhaps think about them for a bit to see if and how they still apply, and apply them by hand-editing the source code yourself.

When recreating a new git format patch with:

Code Block
%$ git format-patch master --stdout -U15 > patch_file.patch

it puts your name and the current date near the top of the file.  If the only changes that you have made are in the context lines, please keep the original author's credit intact by copying the name and date from the original patch that you started from, then upload that.


If you are a screener testing a patch, you can create a new branch and apply the patch to start working with it:

Code Block
$ git checkout -b testxyz
$ git am --keep-cr -s --ignore-whitespace < patch_file.patch

And you can throw that branch away when you're done with:

Code Block
$ git checkout master
$ git branch -D testxyz 

How To Run All Clojure Tests

Code Block
$ mvn clean test

To reduce the duration of the pseudo-randomly generated generative tests from 60 sec down to 1 sec (for example), edit the file src/script/run_test_generative.clj and change the 60000 number.  Just be careful not to include such changes in any patches you submit.  (The file was called src/scripts/run_tests.clj in Clojure 1.6.0 and earlier)

Run An Individual Test


First, build the latest Clojure without running any tests:


Code Block
$ mvn package



ant jar
# If no compilation errors, 'ant jar' creates clojure.jar in Clojure tree root dir

# Or, if you prefer Maven
$ mvn -Dmaven.test.skip=true clean package
# If no compilation errors, mvn command above creates target/clojure-1.



The commands above build a Clojure jar file, but neither compile nor run the tests.

Start a repl and run individual tests from it:


Code Block
$# java -cp test:Replace clojure.jar with target/clojure-1.67.0-master-SNAPSHOT.jar if you ran mvn command
$ java -cp test:clojure.jar clojure.main
Clojure 1.67.0-master-SNAPSHOT
;; We're testing with clojure.test 
=> (require 'clojure.test)
;; Load a test file 
user=> (require '
;; Run it 
user=> (clojure.test/run-tests '
Ran 1 tests containing 17 assertions.
0 failures, 0 errors.
{:type :summary, :pass 17, :test 1, :error 0, :fail 0}   

Start a repl and run a generative test from it:

Generative tests use additional testing jars (installed when you run ./ Thus, you'll need to have some additional classpath which will leave in the maven-classpath file. If you are on *nix, the easiest way to leverage this file is:

Code Block
# Replace clojure.jar with target/clojure-1.7.0-master-SNAPSHOT.jar if you ran mvn command 
$ java -cp `cat maven-classpath`:test:clojure.jar clojure.main 
Clojure 1.7.0-master-SNAPSHOT 
;; Load a test file that uses test.generative
user=> (require 'clojure.test-clojure.reader)
;; Load the test.generative runner ns 
user=> (use 'clojure.test.generative.runner)
;; Test a specification on 1 thread for 200 ms
user=> (run 1 200 #'clojure.test-clojure.reader/types-that-should-roundtrip)
{:iter 60, :seed 1255541066, :test clojure.test-clojure.reader/types-that-should-roundtrip}

Other options for building Clojure

Building Clojure without direct linking

By default, Clojure is built with direct linking enabled.  While this improves performance, it means that if a function A calls a function B, both within Clojure, then using spec to instrument B will leave A still calling the original function B, not the instrumented version.  If you wish to instrument B and have other functions in Clojure call the instrumented version, one way is to build Clojure with direct linking disabled.

Edit the file build.xml to replace "true" with "false" in the following line, which is inside of the section beginning with 'target name="compile-clojure"':

Code Block
<sysproperty key="" value="true"/>

Then use your preferred method of building Clojure from source, e.g.:

Code Block
$ mvn -Dmaven.test.skip=true clean install