jbig2dec fails to build on macOS 11.0 (Big Sur)

[moyang (Moyang Wang)]

It fails on configuration stage. Full log is attached.

configure:3441: checking whether the C compiler works
configure:3463: /usr/bin/clang -pipe -Os -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -arch x86_64 -I/opt/local/include -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -L/opt/local/lib -Wl,-headerpad_max_install_names -Wl,-syslibroot,/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -arch x86_64 conftest.c  >&5
clang: error: invalid version number in 'MACOSX_DEPLOYMENT_TARGET=11.0'
configure:3467: $? = 1
configure:3505: result: no
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME "jbig2dec"
| #define PACKAGE_TARNAME "jbig2dec"
| #define PACKAGE_VERSION "0.19"
| #define PACKAGE_STRING "jbig2dec 0.19"
| #define PACKAGE_BUGREPORT "gs-devel@ghostscript.com"
| #define PACKAGE_URL ""
| #define PACKAGE "jbig2dec"
| #define VERSION "0.19"
| /* end confdefs.h.  */
| 
| int
| main ()
| {
| 
|   ;
|   return 0;
| }
configure:3510: error: in `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_graphics_jbig2dec/jbig2dec/work/jbig2dec-0.19':
configure:3512: error: C compiler cannot create executables
See `config.log' for more details