Thanks for answers. As it turned out, the problem was the script that was used to invoke it. / configure. Inside the script itself, there was extra space above the bindir configuration flag. So that...
'- exec-prefix = / usr' \ _ <- extra space indicated by the underscore.
'--bindir = / usr / bin' \
Thus, the escape character avoided the space, not the return.
uh.
Hope this helps someone lose the second day, trying to dig deeper than the obvious.
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