Matrix builds not working

Whatever software is behind currently seems not to be working - I've tested from my office desktop machine browser, from a cloud VM I have access to in Singapore, and using .

For example: looking at the '[`vector`][vector]' package under the 'Status' heading on the right-hand side, I should be able to get to a matrix of build results for that package by following the link to ; but instead, the bulk of that page seems to be just an empty `div`.

The URL should serve up a status "badge" for `vector` as an SVG, but instead, that URL currently gives a 500 status error, plus the error text:

```
A web handler threw an exception. Details:
libpq: failed (FATAL: could not open file "base/16582/2601": Read-only file system
)
```

From looking at the Wayback Machine, it seems that the badge URL was working on 18th December --

```
curl http://web.archive.org/web/20211218201456/https://matrix.hackage.haskell.org/api/v2/packages/vector/badge
```

correctly gives back an SVG image.

[vector]: https://hackage.haskell.org/package/vector

I also note that currently reports that hackage is "Operational" - which I guess is true, but perhaps it might be worth adding a check of matrix.hackage.haskell.org to that health check as well?