tpm2-tss 2.1.0-1 depends on uriparser and uthash in accordance to upstream's INSTALL.md. These install instructions are somewhat outdated: the dependency on uriparser has been removed a while back, and uthash is only used in the integration tests, so it should be in checkdepends.

I collected the actual dependency situation of tpm2-tss in https://github.com/tpm2-software/tpm2-tss/pull/1247, which has been approved by one of the project's maintainers, so INSTALL.md should now reflect the current state. Thus the current dependencies are

depends=('libgcrypt')
makedepends=('doxygen') # (currently) optional, adds some additional man pages
checkdepends=('cmocka' 'ibm-sw-tpm2' 'net-tools' 'procps-ng' 'uthash')

Perhaps the dependency changes can be held back until the next release 2.2.0, which will probably still happen this month (a release candidate has already been tagged). The new version will require changes anyway: 'libgcrypt' will be removed from depends in favour of 'openssl', and 'doxygen' will be a required makedepends.