I ran ent under perf with this command:
```
$ perf record -g -F 999 ent tag 7e2a3a59fb6b77403ff1035255367607
```

This produced `perf.data`, which i converted to the format supported by the firefox profile tool:
```
$ perf script -F +pid > /tmp/test.perf
```

I uploaded this to the firefox visualizer at <https://profiler.firefox.com/>.

If i'm interpreting this correctly i think it's showing that we spend
most of our time running `git log` in different ways to determine the
author and creation-time of the issues.

If so, lazy load (95a8190f4bbdcafbb4c72db81dfc2aa6) should speed up ent
a lot.