snmp_exporter: No debug log, info via HTTP, or metric on internal parsing error

I am running snmp_exporter with the example config only amended in the default module by the following:

  version: 2
  auth:
    community: SomeCommunityString

Testing a switch via wget results in an internal server error:

$ wget http://127.0.0.1:9116/snmp?target=switch1 –2017-04-21 08:42:25-- http://127.0.0.1:9116/snmp?target=switch1 Connecting to 127.0.0.1:9116… connected. HTTP request sent, awaiting response… 500 Internal Server Error 2017-04-21 08:42:29 ERROR 500: Internal Server Error.

While the debug log from snmp_exporter gives no useful information on what went wrong:

./snmp_exporter -log.level=debug INFO[0000] Starting snmp exporter (version=0.3.0, branch=master, revision=6f8aa8a24d720b36991f29ffb179b2896e92090b) source=main.go:99 INFO[0000] Build context (go=go1.7.5, user=root@07f1e81a0104, date=20170315-16:01:54) source=main.go:100 INFO[0000] Listening on :9116 source=main.go:114 DEBU[0009] Scraping target ‘switch1’ with module ‘default’ source=main.go:77 DEBU[0009] Walking target “switch1” subtree “1.3.6.1.2.1.1.3” source=collector.go:71 DEBU[0009] Walk of target “switch1” subtree “1.3.6.1.2.1.1.3” completed in 75.952882ms source=collector.go:81 DEBU[0009] Walking target “switch1” subtree “1.3.6.1.2.1.2” source=collector.go:71 DEBU[0013] Walk of target “switch1” subtree “1.3.6.1.2.1.2” completed in 3.508447929s source=collector.go:81 DEBU[0013] Walking target “switch1” subtree “1.3.6.1.2.1.31.1.1” source=collector.go:71 DEBU[0014] Walk of target “switch1” subtree “1.3.6.1.2.1.31.1.1” completed in 964.529721ms source=collector.go:81 DEBU[0014] Scrape of target ‘switch1’ with module ‘default’ took 4.660900 seconds source=main.go:88