Develop standard response to `Database is locked` issue

[figaro]

The operational error Database is locked is reported very frequently. While a remedy has been known for many years, users still add this as an issue to be solved. I propose to provide a more helpful response, giving more immediate guidelines, along the lines of:

Duplicate of issue #3446. To solve this issue, please consult the following pages:

• ​http://trac.edgewall.org/ticket/3446#comment:39
• wiki:PySqlite#OperationalError:databaseislocked
• ​https://www.sqlite.org/rescode.html#locked
• ​http://trac.edgewall.org/wiki/MostFrequentDuplicates

[Ryan J Ollos]

Since we don't have something like ​CannedResponsesPlugin built into Trac, we just link to MostFrequentDuplicates. MostFrequentDuplicates could be expanded to provide more details.

We might be able to show specific error message for this exception, rendering a link that points to a description of the issue with possible remedies. Aside from that, I don't expect anything we do will help reduce the frequency of the reports. Many users seem to just repeatedly open tickets and don't follow-up or bother to read the information we point them to.

[figaro]

Can someone review the additions to MostFrequentDuplicates? The wiki formatting is off.

[Jun Omae]

Replying to figaro:

Can someone review the additions to MostFrequentDuplicates? The wiki formatting is off.

Fixed in wiki:MostFrequentDuplicates@17?action=diff. Removed invisible U+200B at begin of the line.

[figaro]

Changed to minor as the first suggestion is implemented and the second suggestion is of lower priority. Either way, the issue will resolve itself as users move away from Trac 0.12 to upgraded versions that do not exhibit the locking issue.

[Ryan J Ollos]

Replying to Ryan J Ollos:

We might be able to show specific error message for this exception, rendering a link that points to a description of the issue with possible remedies.

We can consider revisiting this in the future, but I'm not sure there is enough value in it.