run_target() does some variable substitutions since 0.57.0. This is a
new behavior, and undocumented, caused by sharing more code with
custom_target(). More consistency is better, so document it now.
custom_target() was doing variable substitution in the past, because it
shared some code with generator(), but that was undocumented. Some
refactoring in 0.57.0 caused it to not replace @CURRENT_SOURCE_DIR@,
@SOURCE_DIR@, and @BUILD_DIR@ anymore. This patch adds back
@CURRENT_SOURCE_DIR@ and document it. It does not add back @SOURCE_DIR@
because it is duplicate with @SOURCE_ROOT@ that has a better name. Also
do not add back @BUILD_DIR@ which is duplicate of @PRIVATE_DIR@, and
not @BUILD_ROOT@ surprisingly, adding to the confusion.
Re-implement it in backend using the same code path as for
custom_target(). This for example handle setting PATH on Windows when
command is an executable.
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082
We automatically convert that to use sys.executable now which is
always available on all platforms (because we're running with it).
On some platforms like NetBSD, `python` doesn't exist, and you must
use a specific python version. On most other distros, `python` is
Python 2, and we don't want to depend on that.
Closes https://github.com/mesonbuild/meson/issues/695
All these scripts were being used as `find_program()`, so we do not
lose any test coverage by doing this.