Using maven's “LATEST” keyword in leiningen pr

I have two leiningen projects. According to this question, maven should allow me to use "LATEST" as a dependency version. It is giving me an error suggesting that the dependency with version "LATEST" can't be found. This answer represents how I'm referencing this project locally with leiningen, if that matters.

How do I get this to work? If this isn't how you reference local dependencies in your project, I'm open to alternative suggestions.

The project files look like this:

(defproject mongo-model "0.0.19-SNAPSHOT"
            :description "A simple way to create model templates for mongodb for write-time data validation"
            :dependencies [[org.clojure/clojure "1.3.0"]]
            :main mongo-model.core)

and

(defproject bayou "0.1.0-SNAPSHOT"
            :description "FIXME: write this!"
            :dependencies [[org.clojure/clojure "1.3.0"]
                           [mongo-model "LATEST"]]
            :main bayou.server)

Running lein deps in the second project gives me this error:

An error has occurred while processing the Maven artifact tasks.
 Diagnosis:

Unable to resolve artifact: Missing:
----------
1) mongo-model:mongo-model:jar:LATEST

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file

  Alternatively, if you host your own repository you can deploy the file there: 
      mvn deploy:deploy-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

  Path to dependency: 
    1) org.apache.maven:super-pom:jar:2.0
    2) mongo-model:mongo-model:jar:LATEST

----------
1 required artifact is missing.

for artifact: 
  org.apache.maven:super-pom:jar:2.0

from the specified remote repositories:
  clojars (http://clojars.org/repo/),
  central (http://repo1.maven.org/maven2)



Exception in thread "main" Unable to resolve artifact: Missing:
----------
1) mongo-model:mongo-model:jar:LATEST

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file

  Alternatively, if you host your own repository you can deploy the file there: 
      mvn deploy:deploy-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

  Path to dependency: 
    1) org.apache.maven:super-pom:jar:2.0
    2) mongo-model:mongo-model:jar:LATEST

----------
1 required artifact is missing.

for artifact: 
  org.apache.maven:super-pom:jar:2.0

from the specified remote repositories:
  clojars (http://clojars.org/repo/),
  central (http://repo1.maven.org/maven2)

 (NO_SOURCE_FILE:0)
    at clojure.lang.Compiler.eval(Compiler.java:5440)
    at clojure.lang.Compiler.eval(Compiler.java:5391)
    at clojure.core$eval.invoke(core.clj:2382)
    at clojure.main$eval_opt.invoke(main.clj:235)
    at clojure.main$initialize.invoke(main.clj:254)
    at clojure.main$script_opt.invoke(main.clj:270)
    at clojure.main$main.doInvoke(main.clj:354)
    at clojure.lang.RestFn.invoke(RestFn.java:457)
    at clojure.lang.Var.invoke(Var.java:377)
    at clojure.lang.AFn.applyToHelper(AFn.java:172)
    at clojure.lang.Var.applyTo(Var.java:482)
    at clojure.main.main(main.java:37)
Caused by: Unable to resolve artifact: Missing:
----------
1) mongo-model:mongo-model:jar:LATEST

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file

  Alternatively, if you host your own repository you can deploy the file there: 
      mvn deploy:deploy-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

  Path to dependency: 
    1) org.apache.maven:super-pom:jar:2.0
    2) mongo-model:mongo-model:jar:LATEST

----------
1 required artifact is missing.

for artifact: 
  org.apache.maven:super-pom:jar:2.0

from the specified remote repositories:
  clojars (http://clojars.org/repo/),
  central (http://repo1.maven.org/maven2)


    at org.apache.maven.artifact.ant.DependenciesTask.doExecute(DependenciesTask.java:175)
    at org.apache.maven.artifact.ant.AbstractArtifactTask.execute(AbstractArtifactTask.java:678)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:90)
    at clojure.lang.Reflector.invokeNoArgInstanceMember(Reflector.java:265)
    at leiningen.deps$do_deps.invoke(deps.clj:131)
    at leiningen.deps$deps.doInvoke(deps.clj:195)
    at clojure.lang.RestFn.invoke(RestFn.java:410)
    at clojure.lang.Var.invoke(Var.java:365)
    at clojure.lang.AFn.applyToHelper(AFn.java:161)
    at clojure.lang.Var.applyTo(Var.java:482)
    at clojure.core$apply.invoke(core.clj:542)
    at leiningen.core$apply_task.invoke(core.clj:228)
    at leiningen.core$_main.doInvoke(core.clj:294)
    at clojure.lang.RestFn.invoke(RestFn.java:410)
    at clojure.lang.AFn.applyToHelper(AFn.java:161)
    at clojure.lang.RestFn.applyTo(RestFn.java:132)
    at clojure.core$apply.invoke(core.clj:542)
    at leiningen.core$_main.invoke(core.clj:297)
    at user$eval42.invoke(NO_SOURCE_FILE:1)
    at clojure.lang.Compiler.eval(Compiler.java:5424)
    ... 11 more
Caused by: org.apache.maven.artifact.resolver.MultipleArtifactsNotFoundException: Missing:
----------
1) mongo-model:mongo-model:jar:LATEST

  Try downloading the file manually from the project website.

  Then, install it using the command: 
      mvn install:install-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file

  Alternatively, if you host your own repository you can deploy the file there: 
      mvn deploy:deploy-file -DgroupId=mongo-model -DartifactId=mongo-model -Dversion=LATEST -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

  Path to dependency: 
    1) org.apache.maven:super-pom:jar:2.0
    2) mongo-model:mongo-model:jar:LATEST

----------
1 required artifact is missing.

for artifact: 
  org.apache.maven:super-pom:jar:2.0

from the specified remote repositories:
  clojars (http://clojars.org/repo/),
  central (http://repo1.maven.org/maven2)


    at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolveTransitively(DefaultArtifactResolver.java:324)
    at org.apache.maven.artifact.ant.DependenciesTask.doExecute(DependenciesTask.java:170)
    ... 34 more

There are two things at play here: The standard dependency resolution and the convenience of the the checkouts directory.

The `checkouts` directory

The functionality of the checkouts directory is pretty simple: Leiningen expects to find one or more directories there, each containing another Leiningen project. Usually you create symlinks to your other projects here. For each of the linked projects, the source-path, compile-path and resources-path are added to the classpath. (By default - the list of directories can be configured.)

This means that the namespaces of the linked projects are available in the parent project, no matter if they are included in the dependencies or not. You should still include them in the dependencies though, so other people can work with your codebase.

Dependencies

The dependency resolution mechanism doesn't care about the checkouts directory. It tries to find all dependencies in the local and remote Maven repositories. If you have a dependency on a local project which you never installed in a repository, then it cannot be found, and Leiningen will bail out with an error like the one shown in your question, even if the project is linked in the checkouts directory.

You need to install the artifacts you are depending on at least once in your local repository. This is as easy as calling lein install. You don't need to do this after every change, since you're always using the latest code via the checkouts symlink.

Regarding the use of LATEST: I would say it is encouraged to use fixed version numbers for the dependencies. This is the only way to prevent that a once successful build will suddenly break because of changes in the dependencies. See also this question: How do I tell Maven to use the latest version of a dependency?