I'm experiencing the same issue. I've also tried escaping in a variety of ways and all of them seem to fail.

CODE_SIGN_IDENTITY=iPhone\ Distribution:\ MangoDango,\ Inc
CODE_SIGN_IDENTITY="iPhone Distribution: MangoDango, Inc"
CODE_SIGN_IDENTITY="iPhone\ Distribution:\ MangoDango,\ Inc"
CODE_SIGN_IDENTITY='iPhone Distribution: MangoDango, Inc'
CODE_SIGN_IDENTITY=\"iPhone Distribution: MangoDango, Inc\"
CODE_SIGN_IDENTITY=iPhone\ Distribution\:\ MangoDango\,\ Inc

There doesn't seem to be any other way in the xcode plugin to specify code signing identities. It allows you to specify a provisioning profile, but not the code sign identity for the underlying xcrun command. Furthermore, there is a bug with that area as well. See JENKINS-14028.

Any other suggestions than the ones mentioned above?

I found a great workaround for building with jenkins.

Firstly, before setting up a job, download a jenkins plugin called:

Parameterized Trigger Plugin

https://wiki.jenkins-ci.org/display/JENKINS/Parameterized+Trigger+Plugin

Once you do that, create your job and while creating the job, select the

'This build is parameterized' checkbox

Create a String Parameter. I called mine CODE_SIGN_IDENTITY.

So the name field in the String Parameter should be:

--------------

Name: CODE_SIGN_IDENTITY

Default Value: iPhone Developer: XXX XXXXX

Description: Whatever you want to put there

--------------

Then in your Xcode Plugin, find the 'Custom xcodebuild arguments' field.

In the Custom xcodebuild arguments field, place the following value:

CODE_SIGN_IDENTITY=${CODE_SIGN_IDENTITY}

Finish setting up your job and you should be all set!

This will bypass the white space issue. The plugin is a life saver as it works wonderfully and you can customize your build with other parameters.

Code changed in jenkins
User: Victor Barros
Path:
src/main/java/au/com/rayh/XCodeBuilder.java
src/test/java/au/com/rayh/XCodeBuilderTest.java
http://jenkins-ci.org/commit/xcode-plugin/8b0e0525b9583fbfd90cebe56882a0bd0b5abf5b
Log:
fix for issue JENKINS-12800
https://issues.jenkins-ci.org/browse/JENKINS-12800

Code changed in jenkins
User: Jerome Lacoste
Path:
pom.xml
src/main/java/au/com/rayh/XCodeBuilder.java
src/test/java/au/com/rayh/XCodeBuilderTest.java
http://jenkins-ci.org/commit/xcode-plugin/d08553a852c2feb61ec016bb0940a3571b613a9d
Log:
Merge pull request #22 from heyzooi/master

fix for issue JENKINS-12800

Compare: https://github.com/jenkinsci/xcode-plugin/compare/17322cab642c...d08553a852c2

I suspect this was fixed back in 2013.