UCM crashes when pulling

[didmar]

I get the following error:

.> pull https://github.com/emiflake/unison-json.git:.releases._v1 external.json.v1
Exception: SQLite3 returned ErrorCan'tOpen while attempting to perform open "/home/didier/.cache/unisonlanguage/gitfiles/https$x3A$$x2F$$x2F$github$dot$com$x2F$emiflake$x2F$unison-json$dot$git/.unison/v2/unison.sqlite3": unable to open database file
ucm: SQLite3 returned ErrorCan'tOpen while attempting to perform open "/home/didier/.cache/unisonlanguage/gitfiles/https$x3A$$x2F$$x2F$github$dot$com$x2F$emiflake$x2F$unison-json$dot$git/.unison/v2/unison.sqlite3": unable to open database file

I have no trouble pulling other libraries, so I assume there is something specific here.