After upgrading to version 1.6 I get the following error on every build.

(I have also uninstalled and reinstalled both GIT plugins with no avail)

FATAL: Null value not allowed as an environment variable: GIT_COMMIT
java.lang.IllegalArgumentException: Null value not allowed as an environment variable: GIT_COMMIT
at hudson.EnvVars.put(EnvVars.java:356)
at hudson.EnvVars.put(EnvVars.java:74)
at hudson.plugins.git.GitSCM.buildEnvVars(GitSCM.java:1151)
at hudson.model.AbstractBuild.getEnvironment(AbstractBuild.java:922)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1009)
at hudson.scm.SCM.checkout(SCM.java:484)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1270)
at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:609)
at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:86)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:531)
at hudson.model.Run.execute(Run.java:1717)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:89)
at hudson.model.Executor.run(Executor.java:240)
ERROR: Build step failed with exception
java.lang.IllegalArgumentException: Null value not allowed as an environment variable: GIT_COMMIT
at hudson.EnvVars.put(EnvVars.java:356)
at hudson.EnvVars.put(EnvVars.java:74)
at hudson.plugins.git.GitSCM.buildEnvVars(GitSCM.java:1151)
at hudson.model.AbstractBuild.getEnvironment(AbstractBuild.java:922)
at hudson.plugins.mstest.MSTestPublisher.resolveFilePath(MSTestPublisher.java:99)
at hudson.plugins.mstest.MSTestPublisher.perform(MSTestPublisher.java:79)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:761)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:721)
at hudson.model.Build$BuildExecution.post2(Build.java:183)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:670)
at hudson.model.Run.execute(Run.java:1742)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:89)
at hudson.model.Executor.run(Executor.java:240)