Failure points

make installworld

Output end

At installworld Make: "/usr/src/Makefile"
line 360: Check your date/time

Cure

adjkerntz -i

pkg

Output end

pkg-static: unable to open
vulnxml file (null): Invalid argument

Cure

pkg audit -F

make config

Output end

===> Options unchanged

Cure

pkg install dialog4ports

poudriere ports -u

# Host: github.com
# Port: 443
# Repository: /freebsd/freebsd-ports.git
# Target: /usr/ports
# Have: 4010f7bbc03638d71781ce091bf40a0907fa12fe
# Want: 4010f7bbc03638d71781ce091bf40a0907fa12fe
# Branch: main
[00:00:00] Updating portstree "default" with git...fatal: couldn't find remote ref refs/heads/master

Cure

poudriere ports -d
poudriere ports -c -B main -m git

firefox build failure

Output end

===>  Configuring for rust-1.83.0
Bad system call
=> Sanity check failed: kernel is missing COMPAT_FREEBSD11
=> Aborting build
*** Error code 1

Stop.
make[5]: stopped in /usr/ports/lang/rust
*** Error code 1

Cure

Re-edit applicable kernel config file to include:

options COMPAT_FREEBSD11 # Compatible with FreeBSD11

Stop or disable tailscale breaks networking

tailscale will generate an /etc/resolv.conf file for its use.  If you quit the service, its resolv.conf will still be in effect, loaded but it will be invalid.

Cure

If you saved your resolv.conf prior to working with tailscale, you can restore it, or create a new one similar to below.

nameserver 127.0.0.1
nameserver 10.0.0.1
#nameserver 192.168.1.1
#nameserver 8.8.4.4
options edns0
#search localnetworkname

Some lines commented out but could be used if you wish.  Check man 5 resolver

unable to connect to github.com

Output end

# git clone -b master --single-branch --depth 1 git://github.com/freebsd/freebsd.git /usr/src
Cloning into '/usr/src'...
fatal: unable to connect to github.com:
github.com[0: 140.82.113.4]: errno=Operation timed out

Cure

 Github changed security in September 2021 

Change the url to use https: instead of git:

git clone -b master --single-branch --depth 1  https://github.com/freebsd/freebsd.git /usr/src