[Bug bootstrap/92719] MacOS 10.15 Catalina build fails

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92719

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |x86_64-apple-darwin19.0.0
                 CC|                            |iains at gcc dot gnu.org
   Target Milestone|---                         |10.0
              Build|                            |x86_64-apple-darwin19.0.0

--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> ---
please could you identify the version of Xcode and the SDK in use?
(anything less than 11.3beta is known to have problems).

you have some configuration options that don't apply to 10.15: 

--enable-multilib (this would just break later)

and some that are unnecessary:

--enable-bootstrap (default)
lto in the languages (default)

It is likely the --enable-host-shared option that is causing some difficulty
here, it is rarely used/tested.

(I will try to repeat that locally)

It seems that your GMP installation is in /usr/local (or somehow found
automatically)?

This could also be a problem when using a sysroot (/usr/local is not added at
present)

see  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90834#c13

could you check --- 

../configure --prefix=$PWD/usr --with-sysroot=$OSX_SDK_PATH
--enable-languages=c,c++,fortran --with-gmp=/path/to/gmp/prefix