Unable to install gcc6 in macOS Big Sur 11.1

[YuncongMa (Yuncong Ma)]

Hi! I successfully installed MacPorts 2.6.4 in my Mac Pro 2019 with macOS Big Sur 11.1. I got errors when I tried "sudo port install gcc6". The error messages are as follows: ---> Fetching archive for libgcc7 Warning: Your DNS servers incorrectly claim to know the address of nonexistent hosts. This may cause checksum mismatches for some ports. See this page for more information: <​https://trac.macports.org/wiki/MisbehavingServers> ---> Attempting to fetch libgcc7-7.5.0_0.darwin_20.x86_64.tbz2 from ​https://ywg.ca.packages.macports.org/mirror/macports/packages/libgcc7 ---> Attempting to fetch libgcc7-7.5.0_0.darwin_20.x86_64.tbz2 from ​https://mse.uk.packages.macports.org/libgcc7 ---> Attempting to fetch libgcc7-7.5.0_0.darwin_20.x86_64.tbz2 from ​https://lil.fr.packages.macports.org/libgcc7 ---> Building libgcc7 Error: Failed to build libgcc7: command execution failed Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc7/libgcc7/main.log for details. Error: Follow ​https://guide.macports.org/#project.tickets to report a bug. Error: Processing of port gcc6 failed