OS: 13.0-STABLE stable/13-ddb7a5056, GENERIC kernel, amd64
mail/thunderbird (78.10.0) fails to build if the LTO option is enabled. Build/installation was attempted from Ports (not poudriere or portmaster).
thunderbird-78.10.0 builds just fine with LTO disabled.
This is similar to bug #253539 and bug #253771 for www/firefox.
I created a log file, but the linker error messages are identical to the output posted in bug #253539. I can nevertheless attach all or a snippet of the failed build log if requested.
On this same system, www/firefox (88.0,2) builds just fine with LTO enabled, but for now it's necessarily to disable LTO in order to build latest mail/thunderbird.
I do not have any compiler flags set in /etc/make.conf, and am using the standard LLVM 11.0.1 compiler suite bundled with FreeBSD 13.0.