With the following code, the dataview windows of datasets frauen, maenner and alle are corrupted. The produced save file "alle.sav" is correct. The code also work in non-gui pspp.

I think the window focussing which changes the active dataset somehow interferes with the activation and creation in the syntax file.

dataset display.
dataset declare maenner.
dataset display.
dataset activate maenner.
dataset display.

input program.
string sex (A4).
loop #i = 1 to 1000.
 compute weight  = rv.normal (56, 3).
 end case.
end loop.
end file.
end input program.
compute sex = "male".

dataset display.

dataset declare frauen.
dataset display.
dataset activate frauen.
dataset display.

input program.
string sex (A4).
loop #i = 1 to 1000.
 compute weight  = rv.normal (60, 3).
 end case.
end loop.
end file.
end input program.
compute sex = "fem".

dataset declare alle
dataset activate alle
add files file = maenner
  /file=frauen.

save outfile = alle.sav.

Opening psppire, executing this code twice by pushing "Execute all" in the syntax window without changing focus to another window, crashes psppire with the following message:

Assertion failed: (start + n <= ds->n_columns), function datasheet_delete_columns, file ../pspp/src/data/datasheet.c, line 388.
Abort trap: 6
FriedrichsMacBook:build fritz$

Tested on MacOS.