Unable to change locale (C.UTF-8)

I was looking forward to using your program, but it won’t run.

Terminal output:

bashcaster-master]$ asciinema rec
/bin/sh: warning: setlocale: LC_ALL: cannot change locale (C.UTF-8)
asciinema needs an ASCII or UTF-8 character encoding to run. Check the output of locale command.
bashcaster-master]$ locale
LANG=en_US.UTF-8
LC_CTYPE=“en_US.UTF-8”
LC_NUMERIC=“en_US.UTF-8”
LC_TIME=en_US.UTF-8
LC_COLLATE=“en_US.UTF-8”
LC_MONETARY=en_US.UTF-8
LC_MESSAGES=en_US.UTF-8
LC_PAPER=en_US.UTF-8
LC_NAME=“en_US.UTF-8”
LC_ADDRESS=en_US.UTF-8
LC_TELEPHONE=“en_US.UTF-8”
LC_MEASUREMENT=en_US.UTF-8
LC_IDENTIFICATION=“en_US.UTF-8”
LC_ALL=

I am using https://manjaro.org Linux.

Have you tried setting LC_ALL to anything? Have a go and see if C.UTF-8 does anything to resolve it (and keep a look out for other unintended effects)

The empty LC_ALL may be the culprit. Either make sure it’s not set, or set it to a non-blank value that’s UTF-8.