>>> Emerging : portage://app-crypt/simple-tpm-pk11-0.06-r2:run?{[]}

These are the packages that would be merged, in order:

Calculating dependencies... done!

 └─step  1─┤ verify  app-crypt/tpm-tools (unsatisfied constraints, assumed installed)
             │ verify  app-crypt/tpm-tools (unsatisfied constraints, assumed running)
             │ download  portage://app-crypt/simple-tpm-pk11-0.06-r2
             │           └─ file ─┤ 28.31 Kb  	 simple-tpm-pk11-0.06.tar.gz
             │ download  portage://app-crypt/trousers-0.3.15-r1
             │           └─ file ─┤ 4.48 Mb  	 trousers-0.3.15.tar.gz
             │ download  portage://dev-libs/opencryptoki-3.6.1-r1
             │           └─ file ─┤ 1.02 Mb  	 opencryptoki-3.6.1.tgz

Total: 3 actions (3 downloads), grouped into 1 step.
       5.53 Mb to be downloaded.



Error The proof for your build plan contains domain assumptions. Please verify:


>>> Domain assumptions

- REQUIRED_USE violation: 
  app-crypt/tpm-tools
  No ebuild satisfies USE deps for portage://app-crypt/tpm-tools-1.3.9.2-r1 (use_dep_unsat)
  USE deps force:   [pkcs11]
  conflicts with profile use.mask / use.force
  required by: portage://app-crypt/simple-tpm-pk11-0.06-r2

- REQUIRED_USE violation: 
  app-crypt/tpm-tools
  No ebuild satisfies USE deps for portage://app-crypt/tpm-tools-1.3.9.2-r1 (use_dep_unsat)
  USE deps force:   [pkcs11]
  conflicts with profile use.mask / use.force
  required by: portage://app-crypt/simple-tpm-pk11-0.06-r2


>>> Bug report drafts (Gentoo Bugzilla)

---
Summary: portage://app-crypt/simple-tpm-pk11-0.06-r2: unsatisfied_constraints dependency on app-crypt/tpm-tools

Affected package: portage://app-crypt/simple-tpm-pk11-0.06-r2
Dependency: app-crypt/tpm-tools
Phases: [install,run]

Unsatisfiable constraint(s):
  app-crypt/tpm-tools-

Observed:
  portage-ng reports no available candidate satisfies the above constraint(s).
  Available versions in repo set (sample, first 1 of 1): [1.3.9.2-r1]

Potential fix (suggestion):
  Review dependency metadata in portage://app-crypt/simple-tpm-pk11-0.06-r2; constraint set: [constraint(none,,[])].