[0.60.0] Failed custom_target with command as list containing environment.

[bartoszek]

Describe the bug
80c89a6 breaks passing extrenal_program to custom_targat:commad with additional environment variables.
Last working version meson:0.59.3

To Reproduce
Excerpt from gimp meson.build ( reference issue https://gitlab.gnome.org/GNOME/gimp/-/issues/7420 )

perl = find_program('perl5', 'perl', 'perl5.005', 'perl5.004', 'perl')

perlsrcdir = meson.current_source_dir()
perlbindir = meson.current_build_dir()

perl_env = [
PDBGEN_BACKUP=0
perl,
'-I', perlbindir,
'-I', perlsrcdir,
]

enums_pl = custom_target('enums.pl',
input : [ 'enumgen.pl', 'enums-external.pl', enum_headers, ],
output: [ 'enums.pl', ],
command: [
perl_env, '@INPUT0@',
enum_headers,
],
)

meson setup error:

Program PDBGEN_BACKUP=0 found: NO
gimp/pdb/meson.build:107:0: ERROR: Program 'PDBGEN_BACKUP=0' not found

Expected behavior
Interpreter:_func_custom_target_impl() should check if any element of the list passed as command is an instance of external_program instead of bluntly running _func_find_program on command[0].

system parameters

• Os:ArchLinux
• python:3.9.7
• meson:0.60.0

[eli-schwartz]

You are explicitly not allowed to do this, command is NOT a unix shell command, it is an array containing a program followed by argv.

It will guarantee to break on any platform or backend where the backend (which may or may not be ninja) doesn't use the unix shell. Like Windows.

Since 0.57 the custom_target function accepts an env kwarg that does what you want. Alternatively you may use /usr/bin/env as the custom_target program and pass your env as argv to that.

[eli-schwartz]

Also this should be a duplicate of #8641 (and should not be related to 0.60)