xmlsec1 build fails on Big Sur

[mbaechtold (Martin Bächtold)]

> sudo /opt/local/bin/port install xmlsec1

--->  Fetching archive for ncurses
--->  Attempting to fetch ncurses-6.2_1.darwin_20.x86_64.tbz2 from https://packages.macports.org/ncurses
--->  Attempting to fetch ncurses-6.2_1.darwin_20.x86_64.tbz2.rmd160 from https://packages.macports.org/ncurses
--->  Installing ncurses @6.2_1
--->  Cleaning ncurses
--->  Deactivating ncurses @6.2_0
--->  Cleaning ncurses
--->  Activating ncurses @6.2_1
--->  Cleaning ncurses
--->  Computing dependencies for libgcrypt
--->  Fetching archive for libgcrypt
--->  Attempting to fetch libgcrypt-1.9.1_0.darwin_20.x86_64.tbz2 from https://packages.macports.org/libgcrypt
--->  Attempting to fetch libgcrypt-1.9.1_0.darwin_20.x86_64.tbz2.rmd160 from https://packages.macports.org/libgcrypt
--->  Installing libgcrypt @1.9.1_0
--->  Cleaning libgcrypt
--->  Computing dependencies for libgcrypt
--->  Deactivating libgcrypt @1.9.0_1
--->  Cleaning libgcrypt
--->  Activating libgcrypt @1.9.1_0
--->  Cleaning libgcrypt
--->  Computing dependencies for xmlsec1
--->  Fetching archive for xmlsec1
--->  Attempting to fetch xmlsec1-1.2.31_0+gnutls.darwin_20.x86_64.tbz2 from https://packages.macports.org/xmlsec1
--->  Attempting to fetch xmlsec1-1.2.31_0+gnutls.darwin_20.x86_64.tbz2 from https://lil.fr.packages.macports.org/xmlsec1
--->  Attempting to fetch xmlsec1-1.2.31_0+gnutls.darwin_20.x86_64.tbz2 from https://mse.uk.packages.macports.org/xmlsec1
--->  Building xmlsec1
Error: Failed to build xmlsec1: command execution failed
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_devel_xmlsec1/xmlsec1/main.log for details.
Error: Follow https://guide.macports.org/#project.tickets to report a bug.
Error: Processing of port xmlsec1 failed