2021.04.16 23:08 "Re: [Tiff] tiffcp: LERC codec options refer to zstd even if zstd support is not present", by Even Rouault
Check you have the #define LERC_VERSION_MAJOR in the installed Lerc_c_api.h
The libtiff build needs 'Lerc.h' and 'Lerc_c_api.h'.
Since both are together under 'lerc\src\LercLib', I took both from there. It happens that there is another 'Lerc_c_api.h' under ' lerc\include'. This is different and this is the one containing the definition you point to. Do they need to be different?
If I use the one under 'lerc\include' libtiff builds Ok.
Aouch, (I'm not suppposed to be a LercLib developer, although I'm unfortunate now to have sent pull requests). Wasn't aware of that. I didn't had issues, because I just relied on what "make install" installed in the installation prefix, and it seems that's the content of lerc\include I had updated. Anyway, I've just sent a PR to esri/lerc to resync both version of the headers.
My software is free, but my time generally not.