Scala / SBT - dependency not resolved on PaaS (cloudControl & heroku) - scala

Question

I have a simple Scala application built using spray.io. I am using Scala 2.11.2 and SBT 0.13.0. All of my dependencies are listed here:
libraryDependencies ++= Seq(
"com.typesafe.akka" %% "akka-actor" % "2.3.6",
"com.typesafe.akka" %% "akka-slf4j" % "2.3.6",
"io.spray" % "spray-can_2.11" % "1.3.2",
"io.spray" % "spray-routing_2.11" % "1.3.2",
"io.spray" % "spray-json_2.11" % "1.3.1"
)
libraryDependencies += "org.mongodb" %% "casbah" % "2.7.2"
libraryDependencies += "com.stormpath.sdk" % "stormpath-sdk-api" % "1.0.RC4.2"
libraryDependencies += "com.stormpath.sdk" % "stormpath-sdk-httpclient" % "1.0.RC4.2"
While building and running it locally everything is fine but when i try to push / deploy it to PaaS platforms like cloudControl or heroku i am getting below dependency issue:
[info] Resolving org.apache.httpcomponents#httpclient;${httpclient.version} ...
[warn] module not found: org.apache.httpcomponents#httpclient;${httpclient.version}
[warn] ==== local: tried
[warn] /tmp/scala_buildpack_build_dir/.sbt_home/.ivy2/local/org.apache.httpcomponents/httpclient/${httpclient.version}/ivys/ivy.xml
[warn] ==== public: tried
[warn] http://repo1.maven.org/maven2/org/apache/httpcomponents/httpclient/${httpclient.version}/httpclient-${httpclient.version}.pom
[warn] ==== spray repo: tried
[warn] http://repo.spray.io/org/apache/httpcomponents/httpclient/${httpclient.version}/httpclient-${httpclient.version}.pom
[warn] ==== spray nightlies: tried
[warn] http://nightlies.spray.io/org/apache/httpcomponents/httpclient/${httpclient.version}/httpclient-${httpclient.version}.pom
[warn] ==== public: tried
[warn] http://repo1.maven.org/maven2/org/apache/httpcomponents/httpclient/${httpclient.version}/httpclient-${httpclient.version}.pom
...
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: UNRESOLVED DEPENDENCIES ::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: org.apache.httpcomponents#httpclient;${httpclient.version}: not found
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: FAILED DOWNLOADS ::
[warn] :: ^ see resolution messages for details ^ ::
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
[warn] :: com.stormpath.sdk#stormpath-sdk-api;1.0.RC4.2!stormpath-sdk-api.jar
[warn] ::::::::::::::::::::::::::::::::::::::::::::::
sbt.ResolveException: unresolved dependency: org.apache.httpcomponents#httpclient;${httpclient.version}: not found
...
[error] (*:update) sbt.ResolveException: unresolved dependency: org.apache.httpcomponents#httpclient;${httpclient.version}: not found
[error] download failed: com.stormpath.sdk#stormpath-sdk-api;1.0.RC4.2!stormpath-sdk-api.jar
[error] Total time: 59 s, completed May 4, 2015 1:05:37 PM
Inspecting my dependencies using sbt-dependency-graph shows me that not resolved org.apache.httpcomponents:httpclient is a nested dependency of com.stormpath.sdk:stormpath-sdk-httpclient:1.0.RC4.2.
For some reason variable ${httpclient.version} is not resolved during built - but that is all I can figure it out here. Please help!!!

Answer 1

I am not sure what is going on. But excluding the transitive dependency and adding it to SBT explicitily seems to fix the problem, at least the unresolved dependency problem:
libraryDependencies += "com.stormpath.sdk" % "stormpath-sdk-httpclient" % "1.0.RC4.2" exclude("org.apache.httpcomponents","httpclient")
libraryDependencies += "org.apache.httpcomponents" % "httpclient" % "4.2.2"
But keep in mind that we don't really know which version of apache's httpclient stormpath-sdk-httpclient used in its compilation, so you might run into runtime classpath/linking related exceptions. If that happens I recommend asking the developers of stormpath-sdk-httpclient.
EDIT:
you can see the version they used at:
https://github.com/stormpath/stormpath-sdk-java/blob/master/pom.xml#L98