"Stored by value" is more correct way to explain that example.
Mutable vs immutable means that you cannot mutate the value (e.g. list vs tuple in Python), and the example shows that `var2` is actually mutable.
Copying/storing a reference vs value is what what matters in the assignment, in Python `a=b` means `a` and `b` are references to the same list, while in meson `a=b` copies the value of `b` into `a`.
We need to konw on rconfigure which options have already bee set not
just for the super project, but also for the subproject. However, using
first_invocation is not sufficient, as a reconfigure could add a new
subpproject that wasn't present before, and we need to initialize that
project's builtins.
This will help facilitate cache busting in certain situations, and
replaces hand-rolled solutions of writing a length command to remove
various files/folders within the subprojects directory.
I've picked 160 characters as a default because anything less than that
looks terrible and has awful wrapping going on. However, this respects
the $COLUNNS environment variable if set, and otherwise will query the
terminal to determine the size.
This is all achieved through an application of shtuil.get_terminal_size,
textwrap, print formatters, and iteration.
Fixes#6965
Currently if the version returned is not a supported version, then you
get a lovely stack trace. This is not nice. This can be triggered easily
by adding gcc's `-fdirectives-only` flag, which stops the preprocessor
from doing certain macro expansions, including those used to detect
OpenMP.
Fixes#8652