> well, try --enable-libsvtav1 instead ?

With libsvtav1 change the message in the log:

"gcc is unable to create an executable file.
If gcc is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed."

But I think there is no such thing as libsvtav1:

$ pkg-config --libs libsvtav1
Package libsvtav1 was not found in the pkg-config search path.
Perhaps you should add the directory containing `libsvtav1.pc'
to the PKG_CONFIG_PATH environment variable
Package 'libsvtav1', required by 'virtual:world', not found


Instead using SvtAv1Enc:

$ pkg-config --libs SvtAv1Enc
-lSvtAv1Enc


Using lSvtAv1Enc (with "l"):

$ pkg-config --libs lSvtAv1Enc
Package lSvtAv1Enc was not found in the pkg-config search path.
Perhaps you should add the directory containing `lSvtAv1Enc.pc'
to the PKG_CONFIG_PATH environment variable
Package 'lSvtAv1Enc', required by 'virtual:world', not found