Build failure with meson 0.58.0 with documentation enabled

[loqs]

Bug report

Describe the bug

mpd fails to build using meson 0.58.0 when rsync is not installed.
This is very similar to mesonbuild/meson/issues/8641 but the issue is not triggered using meson 0.57.2.

Expected Behavior

meson should not require rsync as the man pages are not being uploaded only generated.

Actual Behavior

build fails with documentation enabled and rsync not installed.

Version

0.22.6.r477.gc3226a319-1

Log

meson --prefix /usr \
        --libexecdir lib \
        --sbindir bin \
        --buildtype plain \
        --auto-features enabled \
        --wrap-mode nodownload \
        -D b_lto=true \
        -D b_pie=true \
        -D documentation=enabled \
        -D adplug=disabled \
        -D sndio=disabled \
        -D shine=disabled \
        -D tremor=disabled \
        build
The Meson build system
Version: 0.58.0
Source dir: /build/mpd-git/src/mpd
Build dir: /build/mpd-git/src/mpd/build
Build type: native build
Project name: mpd
Project version: 0.23~git
C compiler for the host machine: cc (gcc 11.1.0 "cc (GCC) 11.1.0")
C linker for the host machine: cc ld.bfd 2.36.1
C++ compiler for the host machine: c++ (gcc 11.1.0 "c++ (GCC) 11.1.0")
C++ linker for the host machine: c++ ld.bfd 2.36.1
Host machine cpu family: x86_64
Host machine cpu: x86_64
Found git repository at /build/mpd-git/src/mpd
Program /usr/bin/meson found: YES (/usr/bin/meson)
Configuring Version.h using configuration
Compiler for C++ supports arguments -Wvla: YES 
Compiler for C++ supports arguments -Wdouble-promotion: YES 
Compiler for C++ supports arguments -fvisibility=hidden: YES 
Compiler for C++ supports arguments -ffast-math: YES 
Compiler for C++ supports arguments -ftree-vectorize: YES 
Compiler for C++ supports arguments -fno-threadsafe-statics: YES 
Compiler for C++ supports arguments -fmerge-all-constants: YES 
Compiler for C++ supports arguments -Wmissing-declarations: YES 
Compiler for C++ supports arguments -Wshadow: YES 
Compiler for C++ supports arguments -Wpointer-arith: YES 
Compiler for C++ supports arguments -Wcast-qual: YES 
Compiler for C++ supports arguments -Wwrite-strings: YES 
Compiler for C++ supports arguments -Wsign-compare: YES 
Compiler for C++ supports arguments -Wcomma: NO 
Compiler for C++ supports arguments -Wextra-semi: YES 
Compiler for C++ supports arguments -Wheader-hygiene: NO 
Compiler for C++ supports arguments -Winconsistent-missing-destructor-override: NO 
Compiler for C++ supports arguments -Wunreachable-code-break: NO 
Compiler for C++ supports arguments -Wunused: YES 
Compiler for C++ supports arguments -Wused-but-marked-unused: NO 
Compiler for C++ supports arguments -Wno-non-virtual-dtor: YES 
Compiler for C++ supports arguments -ffunction-sections: YES 
Compiler for C++ supports arguments -fdata-sections: YES 
Compiler for C supports arguments -Wvla: YES 
Compiler for C supports arguments -Wdouble-promotion: YES 
Compiler for C supports arguments -fvisibility=hidden: YES 
Compiler for C supports arguments -ffast-math: YES 
Compiler for C supports arguments -ftree-vectorize: YES 
Compiler for C supports arguments -Wmissing-prototypes: YES 
Compiler for C supports arguments -Wshadow: YES 
Compiler for C supports arguments -Wpointer-arith: YES 
Compiler for C supports arguments -Wstrict-prototypes: YES 
Compiler for C supports arguments -Wcast-qual: YES 
Compiler for C supports arguments -Wwrite-strings: YES 
Compiler for C supports arguments -pedantic: YES 
Compiler for C supports arguments -ffunction-sections: YES 
Compiler for C supports arguments -fdata-sections: YES 
Compiler for C++ supports link arguments -Wl,-z,relro: YES 
Compiler for C++ supports link arguments -Wl,-z,now: YES 
Compiler for C++ supports link arguments -Wl,--gc-sections: YES 
Checking for function "getpwnam_r" : YES 
Checking for function "getpwuid_r" : YES 
Checking for function "initgroups" : YES 
Checking for function "fnmatch" : YES 
Checking for function "strndup" : YES 
Checking for function "strcasestr" : YES 
Checking for function "syslog" : YES 
Found pkg-config: /usr/bin/pkg-config (1.7.3)
Run-time dependency Boost found: YES 1.75.0 (/usr)
Run-time dependency liburing found: YES 0.7
Configuring Features.h using configuration
Run-time dependency threads found: YES
Checking for function "pthread_setname_np" with dependency threads: YES 
Header <sys/socket.h> has symbol "AF_INET6" : YES 
Header <sys/socket.h> has symbol "struct ucred" : YES 
Header <sys/socket.h> has symbol "SO_PEERCRED" : YES 
Checking for function "getpeereid" : NO 
Configuring Features.h using configuration
Run-time dependency dbus-1 found: YES 1.12.20
Run-time dependency icu-i18n found: YES 69.1
Dependency smbclient skipped: feature smbclient disabled
Run-time dependency zlib found: YES 1.2.11
Run-time dependency alsa found: YES 1.2.4
Run-time dependency libchromaprint found: YES 1.5.0
Run-time dependency libcurl found: YES 7.76.1
Run-time dependency expat found: YES 2.3.0
Run-time dependency libavformat found: YES 58.76.100
Run-time dependency libavcodec found: YES 58.134.100
Run-time dependency libavutil found: YES 56.70.100
Run-time dependency libavfilter found: YES 7.110.100
Run-time dependency libnfs found: YES 4.0.0
Has header "sys/soundcard.h" : YES 
Run-time dependency libpcre found: YES 8.44
Run-time dependency libpipewire-0.3 found: YES 0.3.27
Run-time dependency libpulse found: YES 14.2
Library sndio skipped: feature sndio disabled
Run-time dependency sqlite3 found: YES 3.35.5
Run-time dependency libsystemd found: YES 248
Run-time dependency libupnp found: YES 1.14.7
Run-time dependency yajl found: YES 2.1.0
Run-time dependency avahi-client found: YES 0.8
Run-time dependency id3tag found: YES 0.15.1b
Run-time dependency samplerate found: YES 0.2.1
Run-time dependency soxr found: YES 0.1.3
Run-time dependency libcdio_paranoia found: YES 10.2+2.0.0
Run-time dependency libmms found: YES 0.6.4
Configuring Features.h using configuration
Run-time dependency libiso9660 found: YES 2.1.0
Library bz2 found: YES
Run-time dependency zziplib found: YES 0.13.72
Configuring Features.h using configuration
Run-time dependency ao found: YES 1.2.2
Run-time dependency jack found: YES 0.125.0
Header <jack/jack.h> has symbol "jack_set_info_function" : YES 
Run-time dependency openal found: YES 1.21.1
Run-time dependency shout found: YES 2.4.5
Configuring Features.h using configuration
Run-time dependency flac found: YES 1.3.3
Run-time dependency opus found: YES 1.3.1
Run-time dependency vorbis found: YES 1.3.7
Run-time dependency vorbisenc found: YES 1.3.7
Run-time dependency ogg found: YES 1.3.4
Dependency adplug skipped: feature adplug disabled
Run-time dependency fluidsynth found: YES 2.1.8
Run-time dependency audiofile found: YES 0.3.6
Library faad found: YES
Library gme found: YES
Library mad found: YES
Run-time dependency libmikmod found: YES 3.3.11
Run-time dependency libmodplug found: YES 0.8.9.0
Library mpcdec found: YES
Run-time dependency libmpg123 found: YES 1.27.2
Run-time dependency sndfile found: YES 1.0.31
Run-time dependency wavpack found: YES 5.4.0
Run-time dependency wildmidi found: YES 0.4.4
Run-time dependency libsidplayfp found: YES 2.1.2
Configuring Features.h using configuration
Library mp3lame found: YES
Run-time dependency twolame found: YES 0.4.0
Dependency shine skipped: feature shine disabled
Configuring Features.h using configuration
Configuring Features.h using configuration
Run-time dependency libmpdclient found: YES 2.19
Configuring config.h using configuration
Configuring mpd.service using configuration
Configuring mpd.service using configuration
Program sphinx-build found: YES (/usr/bin/sphinx-build)
Program rsync found: NO

doc/meson.build:27:2: ERROR: Program 'rsync' not found

A full log can be found at /build/mpd-git/src/mpd/build/meson-logs/meson-log.txt

[MaxKellermann]

That's a breaking Meson change which is not documented. Sigh.