Unable to read input stream
In the process of committing build outputs to disk (here, copying data from a temporary backing store location to its final location on disk), Electric Make (eMake) was unable to read from a backing store file.
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. However, this error is very unlikely to occur in practice because the file being read was created by eMake itself earlier in the build.
The fix depends on the cause of the error.