Doubling the backslash suppresses special newline handling in GNU make. I don’t see anything in the standard that allows this. It defines an escaped newline as one preceded by a backslash and doesn’t say anything about backslashes being treated specially otherwise.
Test case: >.POSIX: >test: > echo \\ > true Expected result: the command line >echo \\ >true being run. >\ >true being written to the standard output. Actual result: two command lines >echo \\ and >true being run. >\ being written to the standard output.
