This quoting is not necessary and in fact actively harmful, because the ./configure command is not passed to a shell as a string where word-splitting happens, but as an argv array which the process will use as-is.
As an example, previously providing the --with-library=/tmp/foo flag would result in the --with-library='/tmp/foo' flag being passed as the argument, which then would be interpreted as if "--with-library='/tmp/foo'" was entered into a shell. In other words: The library was expected to be found in a directory literally starting with a single-quote.
This quoting is not necessary and in fact actively harmful, because the
./configure
command is not passed to a shell as a string where word-splitting happens, but as an argv array which the process will use as-is.As an example, previously providing the
--with-library=/tmp/foo
flag would result in the--with-library='/tmp/foo'
flag being passed as the argument, which then would be interpreted as if"--with-library='/tmp/foo'"
was entered into a shell. In other words: The library was expected to be found in a directory literally starting with a single-quote.