In the process of committing build outputs to disk (here, creating a directory that was created during the build), Electric Make (eMake) was unable to create the specified directory. The OS error message provides the specific cause of the failure.
Because the error involves an external system in this context (the filesystem on the eMake host), the list of possible causes for this error is virtually limitless: a corrupted filesystem; hardware failure; insufficient permissions; and so on. Refer to the specific OS error message to determine the cause of the failure.
One possible cause for this error is that another process has modified the build output area while eMake is running. This can lead to unpredictable results and should be avoided if possible.