Steps to reproduce:
1. Navigate in web UI to Admin -> SNMP MIB Compiler
2. Upload definitions for RFC-1213 and RFC-1155-SMI
3. Compile RFC-1155, then RFC-1213
Expected result: compile succeeds
Actual result: compiler reports a missing dependency on RFC-1212
The problem is that RFC-1212, which defines the fundamental OBJECT-TYPE macro, also tries to import DisplayString from RFC-1158, which is unnecessary because RFC-1213 obsoletes RFC-1158 and defines DisplayString internally. The typical way to address this problem is for MIB-handling frameworks to define OBJECT-TYPE internally and then to ignore imports of that macro from RFC-1212 silently. Ours seems to do the former but not the latter.
A workaround is possible by editing the working copy of RFC-1213 and removing the import of OBJECT-TYPE from RFC-1212.