Git – Jenkins hanging at “Fetching upstream changes from origin”

I'm trying to set up Jenkins on a Windows Server 2012 machine, and I'm having a lot of difficulty.

Things I've done:

• Created a password-less id_rsa, and id_rsa.pub
• Created a known_hosts file for bitbucket.org using ssh.exe -T bitbucket.org and accepting to add the host.
• Added E: to System-wide HOME Variable
• I've added those files to C:/Windows/SysWOW64/config/systemprofile/.ssh as well as E:/.ssh
• I've linked my public key to Bitbucket as a deployment key.
• I've triple-checked all my URLs, usernames, etc.
• I've even manually pulled from the repository to setup an initial base in C:/Program Files (x86)/Jenkins/jobs/MyProject/workspace/

And yet it still hangs at

Building in workspace C:\Program Files (x86)\Jenkins\jobs\MyProject\workspace
Checkout:workspace / C:\Program Files (x86)\Jenkins\jobs\MyProject\workspace - hudson.remoting.LocalChannel@13ca972
Using strategy: Default
Fetching changes from 1 remote Git repository
Fetching upstream changes from origin

I've given it about 20 minutes, so it's not a speed / size of the repo issue. If I cancel, this is what is returned:

ERROR: Problem fetching from origin / origin - could be unavailable. Continuing anyway
hudson.plugins.git.GitException: Error performing command: C:\Program Files     (x86)\Git\bin\git.exe fetch -t origin +refs/heads/*:refs/remotes/origin/*
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:780)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommand(CliGitAPIImpl.java:739)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.fetch(CliGitAPIImpl.java:160)
at hudson.plugins.git.GitAPI.fetch(GitAPI.java:230)
at hudson.plugins.git.GitSCM.fetchFrom(GitSCM.java:793)
at hudson.plugins.git.GitSCM.access$000(GitSCM.java:57)
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:976)
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:942)
at hudson.FilePath.act(FilePath.java:865)
at hudson.FilePath.act(FilePath.java:838)
at hudson.plugins.git.GitSCM.determineRevisionToBuild(GitSCM.java:942)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1101)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1364)
at hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:670)
at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:88)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:575)
at hudson.model.Run.execute(Run.java:1575)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)
Caused by: java.lang.InterruptedException
at java.lang.ProcessImpl.waitFor(Native Method)
at hudson.Proc$LocalProc.join(Proc.java:319)
at hudson.Launcher$ProcStarter.join(Launcher.java:360)
at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:769)
... 19 more
ERROR: Could not fetch from any repository
FATAL: Could not fetch from any repository
hudson.plugins.git.GitException: Could not fetch from any repository
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:981)
at hudson.plugins.git.GitSCM$2.invoke(GitSCM.java:942)
at hudson.FilePath.act(FilePath.java:865)
at hudson.FilePath.act(FilePath.java:838)
at hudson.plugins.git.GitSCM.determineRevisionToBuild(GitSCM.java:942)
at hudson.plugins.git.GitSCM.checkout(GitSCM.java:1101)
at hudson.model.AbstractProject.checkout(AbstractProject.java:1364)
at     hudson.model.AbstractBuild$AbstractBuildExecution.defaultCheckout(AbstractBuild.java:670)
at jenkins.scm.SCMCheckoutStrategy.checkout(SCMCheckoutStrategy.java:88)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:575)
at hudson.model.Run.execute(Run.java:1575)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)
at hudson.model.ResourceController.execute(ResourceController.java:88)
at hudson.model.Executor.run(Executor.java:237)

I'm at my wits end here, so I appreciate all the help I can get.
Here are a choice few articles which I've tried with no improvement.

Authenticate Jenkins CI for Github private repository

Permission denied (publickey) when setting up Jenkins

Hudson Git Plugin not working on windows

http://computercamp.cdwilson.us/jenkins-git-clone-via-ssh-on-windows-7-x64