Two files are including libsigrokdecode.h in `extern "C"`, which is unnecessary and it breaks the use of <type_traits> in gatomic.h. Other files include it without `extern "C"`.
This is the first error message:
In file included from /usr/include/glib-2.0/glib/gatomic.h:31,
/usr/include/c++/10/type_traits:2308:3: error: template with C linkage
2308 | template<typename _CTp, typename _Rp>
Someone has already created a pull request for this: