opam install srt failed on mac 11.5.2

[WitzHsiao]

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫
⬇ retrieved srt.0.2.0  (cached)
⬇ retrieved liquidsoap.2.0.1  (cached)
[ERROR] The compilation of conf-srt.1 failed at "pkg-config --exists srt".

#=== ERROR while compiling conf-srt.1 =========================================#
# context     2.1.2 | macos/x86_64 | ocaml-base-compiler.4.13.1 | https://opam.ocaml.org#3bc4295d
# path        ~/.opam/4.13.1/.opam-switch/build/conf-srt.1
# command     ~/.opam/opam-init/hooks/sandbox.sh build pkg-config --exists srt
# exit-code   1
# env-file    ~/.opam/log/conf-srt-29586-f637e9.env
# output-file ~/.opam/log/conf-srt-29586-f637e9.out



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫
┌─ The following actions failed
│ λ build conf-srt 1
└─
╶─ No changes have been performed

[toots]

Have you installed the umnderlying srt library, either via:

brew install srt

or using opam depext:

opam depext srt

[WitzHsiao]

@toots yes, I did have installed srt already

[toots]

This is most likely an issue with macos/brew and openssl. You should set PKG_CONFIG_PATH to where the openssl keg is installed, here it is:

export PKG_CONFIG_PATH="/opt/homebrew/opt/openssl@3/lib/pkgconfig"
opam install srt