[BUG] macOS build failure on simulator: missing POSIX timers (timer_t, timer_create, itimerspec)

[FelipeMdeO]

Description / Steps to reproduce the issue

I used Nuttx Link as reference:https://nuttx.apache.org/docs/latest/guides/simulator.html#prerequisites-for-macos

While building the NuttX simulator (sim) on macOS, the build fails due to missing POSIX timer types and APIs. The errors indicate that timer_t, timer_create(), timer_settime(), struct itimerspec, and TIMER_ABSTIME are not available in the macOS SDK.
I tried build the project using Clang as toolchain, but without luck.

sim/posix/sim_hosttime.c:40:8: error: unknown type name 'timer_t'; did you mean 'time_t'?
static timer_t  g_timer;
       ^~~~~~~

sim/posix/sim_hosttime.c:64:10: error: call to undeclared function 'timer_create'
  return timer_create(CLOCK_MONOTONIC, &sigev, &g_timer);

sim/posix/sim_hosttime.c:122:21: error: variable has incomplete type 'struct itimerspec'
  struct itimerspec tspec =

sim/posix/sim_hosttime.c:134:10: error: call to undeclared function 'timer_settime'
  return timer_settime(g_timer, TIMER_ABSTIME, &tspec, NULL);

sim/posix/sim_hosttime.c:134:33: error: use of undeclared identifier 'TIMER_ABSTIME'

@acassis do you know if anyone is using Mac to simulate and use Nuttx?

Environment
OS: macOS (reproducible with current macOS + Xcode CLT)
Toolchain: Apple Clang
Target: sim:nsh
NuttX version: master

On which OS does this issue occur?

[OS: Mac]

What is the version of your OS?

MacOS 26.1

NuttX Version

master

Issue Architecture

[Arch: simulator]

Issue Area

[Area: Build System]

Host information

file sysinfo.h not exists
NuttX CFLAGS:
--g
-fomit-frame-pointer
-fno-common
-fvisibility=hidden
-ffunction-sections
-fdata-sections
-Wall
-Wstrict-prototypes
-Wshadow
-Wundef
-Wno-attributes
-Wno-unknown-pragmas
-fno-pic
-isystem /Users/felipemouradeoliveira/nuttx-space/nuttx/include
-D__NuttX__
-DNDEBUG
-U_AIX
-U_WIN32
-U__APPLE__
-U__FreeBSD__
-U__NetBSD__
-U__linux__
-U__sun__
-U__unix__
-U__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__

NuttX CXXFLAGS:
--g
-fomit-frame-pointer
-fno-common
-fvisibility=hidden
-ffunction-sections
-fdata-sections
-Wall
-Wshadow
-Wundef
-Wno-attributes
-Wno-unknown-pragmas
-nostdinc++
-fno-exceptions
-fcheck-new
-fno-rtti
-fno-pic
-isystem /Users/felipemouradeoliveira/nuttx-space/nuttx/include/cxx
-isystem /Users/felipemouradeoliveira/nuttx-space/nuttx/include
-D__NuttX__
-DNDEBUG
-U_AIX
-U_WIN32
-U__APPLE__
-U__FreeBSD__
-U__NetBSD__
-U__linux__
-U__sun__
-U__unix__
-U__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__

NuttX LDFLAGS:
-Wl-dead_strip

NuttX configuration options:
CONFIG_HOST_MACOS=y
CONFIG_APPS_DIR=../apps
CONFIG_BASE_DEFCONFIG=\sim:nsh-dirty
CONFIG_BUILD_FLAT=y
CONFIG_OUTPUT_STRIP_PATHS=y
CONFIG_ARCH_HAVE_SETJMP=y
CONFIG_ARCH_SETJMP_H=y
CONFIG_ARCH_NONE_DEBUG_H=y
CONFIG_FORTIFY_SOURCE=0
CONFIG_NDEBUG=y
CONFIG_DEBUG_ALERT=y
CONFIG_DEBUG_FEATURES=y
CONFIG_DEBUG_ERROR=y
CONFIG_DEBUG_WARN=y
CONFIG_DEBUG_INFO=y
CONFIG_DEBUG_ASSERTIONS=y
CONFIG_DEBUG_ASSERTIONS_EXPRESSION=y
CONFIG_DEBUG_ASSERTIONS_FILENAME=y
CONFIG_ARCH_HAVE_STACKCHECK=y
CONFIG_STACKCHECK_MARGIN=-1
CONFIG_STACK_USAGE_WARNING=0
CONFIG_DEBUG_SYMBOLS=y
CONFIG_DEBUG_SYMBOLS_LEVEL=-g
CONFIG_ARCH_HAVE_CUSTOMOPT=y
CONFIG_DEBUG_NOOPT=y
CONFIG_LTO_NONE=y
CONFIG_DEBUG_OPT_UNUSED_SECTIONS=y
CONFIG_DEBUG_LINK_MAP=y
CONFIG_ARCH_SIM=y
CONFIG_ARCH=\sim
CONFIG_ARCH_CHIP=\sim
CONFIG_HOST_ARM64=y
CONFIG_SIM_TOOLCHAIN_CLANG=y
CONFIG_SIM_WALLTIME_SLEEP=y
CONFIG_SIM_LOOP_INTERVAL=10
CONFIG_SIM_STACKSIZE_ADJUSTMENT=65536
CONFIG_SIM_HOSTFS=y
CONFIG_SIM_OFFLOAD_NUM_BUFFERS=2
CONFIG_SIM_OFFLOAD_BUFFER_NUMBYTES=32767
CONFIG_SIM_UART_DMA=y
CONFIG_SIM_UART_NUMBER=0
CONFIG_SIM_CUSTOM_DATA_SECTION=\
CONFIG_ARCH_TOOLCHAIN_GNU=y
CONFIG_ARCH_TOOLCHAIN_CLANG=y
CONFIG_ARCH_64BIT=y
CONFIG_ARCH_HAVE_TEXT_HEAP=y
CONFIG_ARCH_HAVE_MULTICPU=y
CONFIG_ARCH_HAVE_FORK=y
CONFIG_ARCH_HAVE_POWEROFF=y
CONFIG_ARCH_HAVE_TESTSET=y
CONFIG_ARCH_HAVE_RTC_SUBSECONDS=y
CONFIG_ARCH_HAVE_SYSCALL_HOOKS=y
CONFIG_ARCH_HAVE_BACKTRACE=y
CONFIG_ARCH_HAVE_CPUINFO=y
CONFIG_ARCH_CPUINFO_FREQ_KHZ=0
CONFIG_ARCH_HAVE_TCBINFO=y
CONFIG_BOARD_LOOPSPERMSEC=0
CONFIG_BOOT_RUNFROMEXTSRAM=y
CONFIG_RAM_START=0x0
CONFIG_RAM_SIZE=0
CONFIG_ARCH_BOARD_SIM=y
CONFIG_ARCH_BOARD=\sim
CONFIG_ARCH_HAVE_BUTTONS=y
CONFIG_ARCH_HAVE_IRQBUTTONS=y
CONFIG_BOARD_CRASHDUMP_NONE=y
CONFIG_BOARDCTL=y
CONFIG_BOARDCTL_POWEROFF=y
CONFIG_BOARDCTL_MKRD=y
CONFIG_BOARDCTL_APP_SYMTAB=y
CONFIG_BOARD_MEMORY_RANGE=\
CONFIG_DISABLE_OS_API=y
CONFIG_ARCH_HAVE_TICKLESS=y
CONFIG_USEC_PER_TICK=10000
CONFIG_TIMER_ADJUST_USEC=0
CONFIG_ARCH_HAVE_TIMEKEEPING=y
CONFIG_START_YEAR=2008
CONFIG_START_MONTH=6
CONFIG_START_DAY=1
CONFIG_PREALLOC_TIMERS=8
CONFIG_IRQ_NWORKS=8
CONFIG_IRQ_WORK_SECTION=\
CONFIG_IRQ_WORK_STACKSIZE=2048
CONFIG_INIT_ENTRY=y
CONFIG_INIT_ARGS=\
CONFIG_INIT_STACKSIZE=2048
CONFIG_INIT_PRIORITY=100
CONFIG_INIT_ENTRYPOINT=\nsh_main
CONFIG_INIT_ENTRYNAME=\nsh_main
CONFIG_ETC_ROMFS=y
CONFIG_ETC_ROMFSMOUNTPT=/etc
CONFIG_ETC_ROMFSDEVNO=1
CONFIG_ETC_ROMFSSECTSIZE=64
CONFIG_ETC_FATDEVNO=2
CONFIG_ETC_FATSECTSIZE=512
CONFIG_ETC_FATNSECTORS=1024
CONFIG_ETC_FATMOUNTPT=/tmp
CONFIG_RR_INTERVAL=0
CONFIG_TASK_NAME_SIZE=31
CONFIG_SCHED_HAVE_PARENT=y
CONFIG_SCHED_WAITPID=y
CONFIG_PTHREAD_MUTEX_ROBUST=y
CONFIG_PTHREAD_MUTEX_DEFAULT_PRIO_NONE=y
CONFIG_SCHED_CPULOAD_NONE=y
CONFIG_SCHED_CPULOAD_TICKSPERSEC=100
CONFIG_SCHED_PROFILE_TICKSPERSEC=1000
CONFIG_SCHED_STACK_RECORD=0
CONFIG_DEV_CONSOLE=y
CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=8
CONFIG_FILE_STREAM=y
CONFIG_SIG_PREALLOC_ACTIONS=4
CONFIG_SIG_ALLOC_ACTIONS=1
CONFIG_SIG_PREALLOC_IRQ_ACTIONS=8
CONFIG_PREALLOC_MQ_MSGS=8
CONFIG_PREALLOC_MQ_IRQ_MSGS=8
CONFIG_MQ_MAXMSGSIZE=32
CONFIG_SCHED_WORKQUEUE=y
CONFIG_SCHED_HPWORK=y
CONFIG_SCHED_HPNTHREADS=1
CONFIG_SCHED_HPWORKPRIORITY=224
CONFIG_SCHED_HPWORKSTACKSIZE=2048
CONFIG_DEFAULT_TASK_STACKSIZE=2048
CONFIG_IDLETHREAD_STACKSIZE=4096
CONFIG_PTHREAD_STACK_MIN=256
CONFIG_PTHREAD_STACK_DEFAULT=2048
CONFIG_PTHREAD_GUARDSIZE_DEFAULT=0
CONFIG_SCHED_BACKTRACE=y
CONFIG_PID_INITIAL_COUNT=16
CONFIG_SCHED_EVENTS=y
CONFIG_DEV_LOOP=y
CONFIG_ONESHOT=y
CONFIG_ONESHOT_COUNT=y
CONFIG_ALARM_ARCH=y
CONFIG_BCH=y
CONFIG_BCH_BUFFER_ALIGNMENT=0
CONFIG_IOEXPANDER=y
CONFIG_IOEXPANDER_DUMMY=y
CONFIG_IOEXPANDER_DUMMY_INT_NCALLBACKS=4
CONFIG_IOEXPANDER_DUMMY_INT_POLLDELAY=500000
CONFIG_IOEXPANDER_INT_ENABLE=y
CONFIG_IOEXPANDER_NPINS=16
CONFIG_DEV_GPIO=y
CONFIG_DEV_GPIO_NPOLLWAITERS=1
CONFIG_DEV_GPIO_NSIGNALS=1
CONFIG_GPIO_LOWER_HALF=y
CONFIG_GPIO_LOWER_HALF_INTTYPE=14
CONFIG_DEV_NULL=y
CONFIG_DEV_ZERO=y
CONFIG_DEV_OPTEE_NONE=y
CONFIG_DRVR_MKRD=y
CONFIG_PIPES=y
CONFIG_DEV_PIPE_MAXSIZE=65535
CONFIG_DEV_PIPE_SIZE=1024
CONFIG_DEV_FIFO_SIZE=1024
CONFIG_DEV_PIPE_VFS_PATH=/var/pipe
CONFIG_DEV_PIPE_NPOLLWAITERS=4
CONFIG_ARCH_HAVE_SERIAL_TERMIOS=y
CONFIG_SERIAL=y
CONFIG_SERIAL_CONSOLE=y
CONFIG_SERIAL_NPOLLWAITERS=4
CONFIG_SERIAL_IFLOWCONTROL=y
CONFIG_SERIAL_TXDMA=y
CONFIG_SERIAL_RXDMA=y
CONFIG_SYSLOG=y
CONFIG_SYSLOG_DEFAULT_MASK=0xff
CONFIG_SYSLOG_CRLF=y
CONFIG_SYSLOG_MAX_CHANNELS=1
CONFIG_SYSLOG_DEVPATH=/dev/ttyS1
CONFIG_SYSLOG_DEFAULT=y
CONFIG_FS_NEPOLL_DESCRIPTORS=8
CONFIG_FS_LOCK_BUCKET_SIZE=0
CONFIG_PSEUDOFS_ATTRIBUTES=y
CONFIG_PSEUDOFS_SOFTLINKS=y
CONFIG_PSEUDOFS_FILE=y
CONFIG_SENDFILE_BUFSIZE=512
CONFIG_FS_HEAPSIZE=0
CONFIG_FS_BACKTRACE=0
CONFIG_FS_MQUEUE_VFS_PATH=/var/mqueue
CONFIG_FS_MQUEUE_NPOLLWAITERS=4
CONFIG_FS_RAMMAP=y
CONFIG_FS_ANONMAP=y
CONFIG_FS_FAT=y
CONFIG_FAT_LCNAMES=y
CONFIG_FAT_LFN=y
CONFIG_FAT_MAXFNAME=32
CONFIG_FAT_LFN_ALIAS_TRAILCHARS=0
CONFIG_FS_ROMFS=y
CONFIG_FS_ROMFS_CACHE_NODE=y
CONFIG_FS_ROMFS_CACHE_FILE_NSECTORS=1
CONFIG_FS_BINFS=y
CONFIG_FS_PROCFS=y
CONFIG_FS_HOSTFS=y
CONFIG_NXFONTS_PACKEDMSFIRST=y
CONFIG_MM_DEFAULT_MANAGER=y
CONFIG_MM_DEFAULT_ALIGNMENT=8
CONFIG_MM_NODE_GUARDSIZE=0
CONFIG_MM_REGIONS=1
CONFIG_MM_MAP_COUNT_MAX=1024
CONFIG_MM_BACKTRACE=-1
CONFIG_MM_FREE_DELAYCOUNT_MAX=0
CONFIG_MM_HEAP_BIGGEST_COUNT=30
CONFIG_MM_HEAP_MEMPOOL_THRESHOLD=-1
CONFIG_PATH_INITIAL=/bin
CONFIG_BINFMT_ELF_RELOCATABLE=y
CONFIG_STDIO_BUFFER_SIZE=64
CONFIG_STDIO_LINEBUFFER=y
CONFIG_NUNGET_CHARS=2
CONFIG_LIBC_LONG_LONG=y
CONFIG_LIBC_NUMBERED_ARGS=y
CONFIG_LIBC_NL_ARGMAX=9
CONFIG_ARCH_LOWPUTC=y
CONFIG_LIBC_RAND_ORDER=1
CONFIG_LIBC_HOMEDIR=/
CONFIG_LIBC_TMPDIR=/tmp
CONFIG_LIBC_MAX_TMPFILE=32
CONFIG_LIBC_MAX_EXITFUNS=1
CONFIG_LIBC_EXECFUNCS=y
CONFIG_POSIX_SPAWN_DEFAULT_STACKSIZE=2048
CONFIG_LIBC_HOSTNAME=\
CONFIG_LIBC_OPEN_MAX=256
CONFIG_NAME_MAX=32
CONFIG_PATH_MAX=256
CONFIG_LINE_MAX=80
CONFIG_LIBC_STRERROR_ERRNUM=y
CONFIG_LIBC_STRSIGNAL=y
CONFIG_LIBC_LOCALE=y
CONFIG_LIBC_LOCALE_CATALOG=y
CONFIG_LIBC_LOCALE_GETTEXT=y
CONFIG_LIBC_LOCALE_PATH=/etc/locale
CONFIG_TLS_NELEM=0
CONFIG_TLS_TASK_NELEM=0
CONFIG_TLS_NCLEANUP=0
CONFIG_LIBC_GAISTRERROR_ERRNUM=y
CONFIG_LIBC_ENVPATH=y
CONFIG_LIBC_FTOK_VFS_PATH=/var/ftok
CONFIG_LIBC_MEMFD_ERROR=y
CONFIG_LIBC_TEMPBUFFER=y
CONFIG_LIBC_MAX_TEMPBUFFER=2
CONFIG_LIBC_TEMPBUFFER_MALLOC=y
CONFIG_LIBC_BACKTRACE_BUFFSIZE=0
CONFIG_LIBC_MUTEX_BACKTRACE=0
CONFIG_BUILTIN=y
CONFIG_STREAM_OUT_BUFFER_SIZE=64
CONFIG_STREAM_HEXDUMP_BUFFER_SIZE=128
CONFIG_STREAM_BASE64_BUFFER_SIZE=128
CONFIG_LIBC_INLINE_QUEUE=y
CONFIG_LIBM_TOOLCHAIN=y
CONFIG_HAVE_CXXINITIALIZE=y
CONFIG_BUILTIN_TOOLCHAIN=y
CONFIG_COVERAGE_NONE=y
CONFIG_COVERAGE_DEFAULT_PREFIX_STRIP=\0
CONFIG_COVERAGE_DEFAULT_PREFIX=/data
CONFIG_PROFILE_NONE=y
CONFIG_EXAMPLES_GPIO=y
CONFIG_EXAMPLES_GPIO_PROGNAME=\gpio
CONFIG_EXAMPLES_GPIO_PRIORITY=100
CONFIG_EXAMPLES_GPIO_STACKSIZE=2048
CONFIG_EXAMPLES_HELLO=y
CONFIG_EXAMPLES_HELLO_PROGNAME=\hello
CONFIG_EXAMPLES_HELLO_PRIORITY=100
CONFIG_EXAMPLES_HELLO_STACKSIZE=2048
CONFIG_FSUTILS_MKFATFS=y
CONFIG_MKFATFS_BUFFER_ALIGNMENT=0
CONFIG_NSH_LIBRARY=y
CONFIG_NSH_PROMPT_STRING=\nsh>
CONFIG_NSH_PROMPT_MAX=32
CONFIG_NSH_PROMPT_ENV=\PS1
CONFIG_NSH_PROMPT_SUFFIX=>
CONFIG_NSH_READLINE=y
CONFIG_NSH_QUOTE=y
CONFIG_NSH_MAXARGUMENTS=7
CONFIG_NSH_ARGCAT=y
CONFIG_NSH_NESTDEPTH=3
CONFIG_NSH_ALIAS=y
CONFIG_NSH_ALIAS_MAX_AMOUNT=1
CONFIG_NSH_PIPELINE=y
CONFIG_NSH_BUILTIN_APPS=y
CONFIG_NSH_FILE_APPS=y
CONFIG_NSH_DISABLE_DATE=y
CONFIG_NSH_DISABLE_LOSMART=y
CONFIG_NSH_DISABLE_LOMTD=y
CONFIG_NSH_DISABLE_MB=y
CONFIG_NSH_DISABLE_MH=y
CONFIG_NSH_DISABLE_MW=y
CONFIG_NSH_DISABLE_SHUTDOWN=y
CONFIG_NSH_DISABLE_TIMEDATECTL=y
CONFIG_NSH_CODECS_BUFSIZE=128
CONFIG_NSH_PROC_MOUNTPOINT=/proc
CONFIG_NSH_FILEIOSIZE=1024
CONFIG_NSH_SYSINITSCRIPT=\init.d/rc.sysinit
CONFIG_NSH_INITSCRIPT=\init.d/rcS
CONFIG_NSH_SCRIPT_REDIRECT_PATH=\
CONFIG_NSH_CONSOLE=y
CONFIG_NSH_ARCHINIT=y
CONFIG_SYSTEM_DD=y
CONFIG_SYSTEM_DD_PROGNAME=\dd
CONFIG_SYSTEM_DD_PRIORITY=100
CONFIG_SYSTEM_DD_STACKSIZE=2048
CONFIG_SYSTEM_DD_STATS=y
CONFIG_SYSTEM_DUMPSTACK=y
CONFIG_SYSTEM_DUMPSTACK_STACKSIZE=2048
CONFIG_SYSTEM_DUMPSTACK_PRIORITY=100
CONFIG_SYSTEM_NSH=y
CONFIG_SYSTEM_NSH_PRIORITY=100
CONFIG_SYSTEM_NSH_STACKSIZE=2048
CONFIG_SYSTEM_NSH_PROGNAME=\nsh
CONFIG_SYSTEM_READLINE=y
CONFIG_READLINE_HAVE_EXTMATCH=y
CONFIG_READLINE_ECHO=y
CONFIG_READLINE_TABCOMPLETION=y
CONFIG_READLINE_MAX_BUILTINS=64
CONFIG_READLINE_MAX_EXTCMDS=64
CONFIG_TESTING_OSTEST=y
CONFIG_TESTING_OSTEST_LOOPS=1
CONFIG_TESTING_OSTEST_STACKSIZE=8192
CONFIG_TESTING_OSTEST_NBARRIER_THREADS=8
CONFIG_TESTING_OSTEST_RR_RANGE=30000
CONFIG_TESTING_OSTEST_RR_RUNS=10
CONFIG_TESTING_OSTEST_WAITRESULT=y

Host system OS:
macOS 26.1 Darwin Felipes-Air 25.1.0 Darwin Kernel Version 25.1.0: Mon Oct 20 19:32:47 PDT 2025; root:xnu-12377.41.6~2/RELEASE_ARM64_T8103 arm64 arm

Host system PATH:
/Users/felipemouradeoliveira/toolchains/xpack-x86_64-elf-gcc-*/bin
/Users/felipemouradeoliveira/Library/xpacks/@xpack-dev-tools/riscv-none-elf-gcc/15.2.0-1.1/.content/bin
/usr/local/bin
/System/Cryptexes/App/usr/bin
/usr/bin
/bin
/usr/sbin
/sbin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin
/opt/pmk/env/global/bin
/opt/homebrew/bin
/Users/felipemouradeoliveira/Library/Python/3.9/bin
/Users/felipemouradeoliveira/.local/bin
/Users/felipemouradeoliveira/Library/Python/3.9/bin
/Users/felipemouradeoliveira/.local/bin

Verification

• I have verified before submitting the report.

[simbit18]

Hi @FelipeMdeO , unfortunately, the errors you encountered are the same ones we have on NuttX Mirror.

====================================================================================
Configuration/Tool: sim/nsh
2026-01-12 03:21:15
------------------------------------------------------------------------------------
  Cleaning...
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
  Configuring...
  Building NuttX...
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
Error: sim/posix/sim_hosttime.c:40:8: error: unknown type name 'timer_t'; did you mean 'time_t'?
   40 | static timer_t  g_timer;
      |        ^~~~~~~
      |        time_t
/Applications/Xcode_16.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types/_time_t.h:31:33: note: 'time_t' declared here
   31 | typedef __darwin_time_t         time_t;
      |                                 ^
Error: sim/posix/sim_hosttime.c:64:10: error: call to undeclared function 'timer_create'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   64 |   return timer_create(CLOCK_MONOTONIC, &sigev, &g_timer);
      |          ^
Error: sim/posix/sim_hosttime.c:122:21: error: variable has incomplete type 'struct itimerspec'
  122 |   struct itimerspec tspec =
      |                     ^
sim/posix/sim_hosttime.c:122:10: note: forward declaration of 'struct itimerspec'
  122 |   struct itimerspec tspec =
      |          ^
Error: sim/posix/sim_hosttime.c:134:10: error: call to undeclared function 'timer_settime'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  134 |   return timer_settime(g_timer, TIMER_ABSTIME, &tspec, NULL);
      |          ^
Error: sim/posix/sim_hosttime.c:134:33: error: use of undeclared identifier 'TIMER_ABSTIME'
  134 |   return timer_settime(g_timer, TIMER_ABSTIME, &tspec, NULL);
      |                                 ^
5 errors generated.
make[1]: *** [sim_hosttime.o] Error 1
make[1]: Target `nuttx' not remade because of errors.
make: *** [nuttx] Error 2
make: Target `all' not remade because of errors.
/Users/runner/work/nuttx/nuttx/sources/nuttx/tools/testbuild.sh: line 385: /Users/runner/work/nuttx/nuttx/sources/nuttx/../nuttx/nuttx.manifest: No such file or directory
  [1/1] Normalize sim/nsh
====================================================================================

https://github.com/NuttX/nuttx/actions/runs/20906117240/job/60059906124#logs

broken [macOS (sim-01)], [macOS (sim-02)] and [macOS (sim-03)]

[FelipeMdeO]

Hello @simbit18, I was able to build the sim env here doing a "work around".
In my case, I changed sim_hosttime.c file using macros to add/remove code specifically to macOS.
Do you have any idea about how is the right way to solve this? Will be good fix it.

[simbit18]

Hi @FelipeMdeO, I don't have a Mac.

Perhaps @pkarashchenko or @yamt can help.

[aditya0yadav]

I’ve used a different approach to fix this. I’ve made some changes to the code and if you’d like to see them, please take a look at this file: https://github.com/aditya0yadav/nuttx-apache-macos/blob/main/sim_hosttime.c

If you follow this idea, please disable GCOV in the kconfig or config file.

[simbit18]

@FelipeMdeO @aditya0yadav Can you please check this PR #18331?
The issue is still not fixed.

sim:nsh on our NuttX Mirror

====================================================================================
Configuration/Tool: sim/nsh
2026-03-05 16:45:18
------------------------------------------------------------------------------------
  Cleaning...
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
  Configuring...
  Building NuttX...
compiler-rt/Make.defs:45: target `bin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
compiler-rt/Make.defs:45: target `kbin/compiler-rt/compiler-rt/lib/builtins' given more than once in the same rule.
Error: sim/posix/sim_hosttime.c:40:8: error: unknown type name 'timer_t'; did you mean 'time_t'?
   40 | static timer_t  g_timer;
      |        ^~~~~~~
      |        time_t
/Applications/Xcode_16.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/_types/_time_t.h:31:33: note: 'time_t' declared here
   31 | typedef __darwin_time_t         time_t;
      |                                 ^
Error: sim/posix/sim_hosttime.c:64:10: error: call to undeclared function 'timer_create'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
   64 |   return timer_create(CLOCK_MONOTONIC, &sigev, &g_timer);
      |          ^
Error: sim/posix/sim_hosttime.c:122:21: error: variable has incomplete type 'struct itimerspec'
  122 |   struct itimerspec tspec =
      |                     ^
sim/posix/sim_hosttime.c:122:10: note: forward declaration of 'struct itimerspec'
  122 |   struct itimerspec tspec =
      |          ^
Error: sim/posix/sim_hosttime.c:134:10: error: call to undeclared function 'timer_settime'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  134 |   return timer_settime(g_timer, TIMER_ABSTIME, &tspec, NULL);
      |          ^
Error: sim/posix/sim_hosttime.c:134:33: error: use of undeclared identifier 'TIMER_ABSTIME'
  134 |   return timer_settime(g_timer, TIMER_ABSTIME, &tspec, NULL);
      |                                 ^
5 errors generated.
make[1]: *** [sim_hosttime.o] Error 1
make[1]: Target `nuttx' not remade because of errors.
make: *** [nuttx] Error 2
make: Target `all' not remade because of errors.
/Users/runner/work/nuttx/nuttx/sources/nuttx/tools/testbuild.sh: line 385: /Users/runner/work/nuttx/nuttx/sources/nuttx/../nuttx/nuttx.manifest: No such file or directory
  [1/1] Normalize sim/nsh
====================================================================================

[aditya0yadav]

@simbit18 that pr right now fixes the issue related to the linker on mac
but citest always fail for that change

I am researching on that .