Bug report

curses.ERR is set with an unsigned conversion, so it is no longer -1:

>>> import curses
>>> curses.ERR
18446744073709551615

It is -1 in 3.15 and earlier. Code that compares the result of window.getch(), which returns -1 when there is no input, with curses.ERR silently stops matching.

The unsigned conversion is needed for the chtype constants, which can set bits beyond a 32-bit long, but ERR is the only signed constant set that way.

Regression in gh-154934, not yet released.

Linked PRs

• gh-156348: Fix the value of curses.ERR #156349