#2883 Recent changes to subtaskMonitor causes runtime error in existing script

[Jeremy Faden]

Autoplot v2026a_7 can't run
https://github.com/autoplot/dev/blob/master/demos/2025/20250421/call_e_b_mms_v4a.jy
because of how it uses the monitors. This worked before, and its use should be supported.

[Jeremy Faden]

1. run https://github.com/autoplot/dev/blob/master/demos/2025/20250421/call_e_b_mms_v4a.jy
2. the error "setTaskProgress called before started" is raised.

[Jeremy Faden]

This is fixed and will be released in v2026a_8. I verified that calling "started" multiple times on a monitor is safe, and getSubtaskMonitor will call started if the parent is not yet started.

[Jeremy Faden]

finished() can be called multiple times, but it prints a stack trace to stderr warning of the error. Repeat calls to started seem more harmless, but started should probably print a warning message too. (I can imagine a multi-threaded application triggering this.)

[Jeremy Faden]

See https://github.com/autoplot/dev/blob/master/bugs/sf/2883/stressMonitor.jy.