v0.19.2

Added

• argparse now supports optional positional arguments
  • like so: p.add_arg("foo", "Foo thing", required=False, nargs="?")
• print() now takes multiple new input arguments:
  • print(*vals, sep=" ", end="", stderr=False, flush=False)
  • sep is the separation character between values, default " "
  • end is the line ending character, default "\n"
  • Output is written to stdout per default, set stderr=True to write to
    stderr instead
  • set flush=True to flush the output
• new --rts-bt-debug flag that launches interactive debugger (gdb) on
  SIGSEGV / SIGILL

Changed

• print() now formats to a temporary buffer before printing to reduce
  interleaving multiple outputs
• printn() has been removed in preference of using print(foo, end="")

Fixed

• KeyError now includes the key as part of the error message
  • e.g. KeyError: getitem: key not in dictionary, key: foobar
  • The string formatting of the error message including the key only happens
    when the str representation of the exception is necessary, so it does not
    incur a performance penalty in normal scenarios
  • The key for which the lookup was attempted is stored in the key attribute
• Homebrew Formula now somewhat decoupled from Stack version [#1627]
  • Idiomatic Homebrew Formulas use system-ghc, i.e. a GHC version installed by
    Homebrew itself and not from Stack. Since we specify a Stack LTS resolver,
    which is a coupled to a particular version of GHC, there is room for a
    version mismatch.
  • The latest occurrence of which was GHC 9.4.8 in Homebrew vs Stack LTS 21.13
    with GHC 9.4.7. A rather silly small mismatch but that nonetheless breaks
    the Homebrew build. This is particularly annoying because it happens only
    after we've made a release, so the feedback is too late and thus a
    correction version must be released to fix the version mismatch (we've
    upgraded to LTS 21.25 with GHC 9.4.8 to align on Homebrew).
  • Now skip-ghc-check is used to skip the GHC version check to allow some
    minor mismatch to happen. We must still ensure that at least the major
    version of GHC is aligned, like GHC 9.4.