Macports failures with BigSur

[pavibhai (Pavan Lanka)]

I recently upgraded to MacOS BigSur. After the upgrade was completed I tried to install the new MacPorts with the pkg installer for BigSur.

When I try to install ports I get errors.

Warning: The macOS 11.0 SDK does not appear to be installed. Ports may not build correctly.
Warning: You can install it as part of the Xcode Command Line Tools package by running `xcode-select --install'.
--->  Fetching archive for gmp
--->  Attempting to fetch gmp-6.2.0_1.darwin_20.x86_64.tbz2 from https://packages.macports.org/gmp
--->  Attempting to fetch gmp-6.2.0_1.darwin_20.x86_64.tbz2 from https://ywg.ca.packages.macports.org/mirror/macports/packages/gmp/gmp
--->  Attempting to fetch gmp-6.2.0_1.darwin_20.x86_64.tbz2 from https://kmq.jp.packages.macports.org/gmp
--->  Fetching distfiles for gmp
--->  Attempting to fetch gmp-6.2.0.tar.bz2 from https://distfiles.macports.org/gmp
--->  Verifying checksums for gmp
--->  Extracting gmp
--->  Applying patches to gmp
--->  Configuring gmp
Error: Failed to configure gmp, consult /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/work/gmp-6.2.0/config.log
Error: Failed to configure gmp: configure failure: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port gnupg2 failed
lanka-imac:~$ less /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/main.log
lanka-imac:~$ less /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_gmp/gmp/work/gmp-6.2.0/config.log

When I look at the config.log, I have the following:

configure:5847: /usr/bin/clang -isysroot/Library/Developer/CommandLineTools/SDKs
/MacOSX.sdk -c conftest.c >&5
clang: error: invalid version number in 'MACOSX_DEPLOYMENT_TARGET=11.0'

I have attached the config.log to the ticket. I can provide other details as needed. Additionally I keep on seeing this warning

Warning: The macOS 11.0 SDK does not appear to be installed. Ports may not build correctly.
Warning: You can install it as part of the Xcode Command Line Tools package by running `xcode-select --install'.

Not sure if these are related, but xcode-select --install tells me that it is already installed.

I have finally tried an ​uninstall, followed by an install but still get the same error.

[pavibhai (Pavan Lanka)]

config.log