I am trying to add to an variable that is already in Jenkins.If i have the following entry in my properties file.
PATH = C:\PROGRAM\BIN;$PATH

and i check the injectedEnvVars.txt file i see that PATH is set to this

PATH=C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;C:\PROGRAM\BIN;

and so on. IT could be 1000 C:\PROGRAM\BIN; printed in the file making the jenkins build run out of memory.

I had a look at the code and it might be where the file is being read. IT might be looping around. This can happen with any variable just not PATH.

This will produce the problem also. There is a loop some where that adds the variable to the variable over and over.
OS=Windows_NT;$OS

This is the exception that is produced by Jenkins.

Archiving artifacts
FATAL: Java heap space
java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Arrays.java:2894)
at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:117)
at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:407)
at java.lang.StringBuilder.append(StringBuilder.java:136)
at hudson.Util.replaceMacro(Util.java:160)
at hudson.Util.replaceMacro(Util.java:127)
at org.jenkinsci.plugins.envinject.service.EnvInjectEnvVars.resolveVars(EnvInjectEnvVars.java:206)
at org.jenkinsci.plugins.envinject.EnvInjectListener$2.buildEnvVars(EnvInjectListener.java:211)
at hudson.model.AbstractBuild.getEnvironment(AbstractBuild.java:942)
at hudson.tasks.ArtifactArchiver.perform(ArtifactArchiver.java:136)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:804)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:776)
at hudson.model.Build$BuildExecution.post2(Build.java:183)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:726)
at hudson.model.Run.execute(Run.java:1628)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:247)