Templates not working for non-http IRIs

When using rml:template to construct an IRI, explicitly indicated with rml:termType, the triples in question are missing from the output, except when they result in a well-formed HTTP URI.

Minimal example:

:mapping a rml:TriplesMap ;
  rml:logicalSource [
    # JSONPath root iterator over { "key": "value" }
  ] ;
  rml:subjectMap [ rml:termType rml:BlankNode ] ;
  rml:predicateObjectMap [
    rml:predicate <urn:example:http> ;
    rml:objectMap [
      rml:termType rml:IRI ;
      rml:template "http://example.org/{key}"
    ]
  ], [
    rml:predicate <urn:example:file> ;
    rml:objectMap [
      rml:termType rml:IRI ;
      rml:template "file:///example/{key}"
    ]
  ], [
    rml:predicate <urn:example:urn> ;
    rml:objectMap [
      rml:termType rml:IRI ;
      rml:template "urn:example:{key}"
    ]
  ], [
    rml:predicate <urn:example:relative> ;
    rml:objectMap [
      rml:termType rml:IRI ;
      rml:template "./{key}"
    ]
  ] .

Output:

_:Blank1 <urn:example:http> <http://example.org/value> .

Start by running the minimal mapping example and tracing how rml:termType rml:IRI with rml:template is handled. Compare the HTTP, file, URN, and relative templates to find why only the HTTP result is emitted. Done means all four expected triples appear in the output.