JetBrains/intellij-community — pull request #15 by xfournet (2012-08-06 12:04:40+00:00)
Title: IDEA-74131 Maven interpolation error: Failed to interpolate field

The synchronized keyword on the method interpolateObject was not enough because the cache in StringSearchModelInterpolator is static, so we need to protect concurrent access whatever the instance of CustomModelInterpolator. Here I simply use the CustomModelInterpolator class as synchronization object.
I never see the error again since I applied this fix.