我第一次遇到这个问题：https ://github.com/facebook/react-native/issues/10088
然后我按照这个解决方案来解决这个问题：https ://github.com/facebook/react-native/issues/910#issuecomment-94181845
现在，当我进入时，npm start我得到[sane] Warning: Lost connection to watchman, reconnecting... 有什么建议么？
更新：当我将我的 MacOS 更新到 MacOS Sierra 时，这种情况开始发生。
更新：所以我尝试运行react-native run-ios它打开一个新的控制台窗口并调用npm start. 它仍然会[sane] Warning: Lost connection to watchman, reconnecting..发出警告，但它会构建捆绑包。所以守望者之间的联系被打破了。这是控制台屏幕截图：
我按照 David 提供的解决方案解决了这个问题，但我必须做一些额外的步骤，因为我已经使用 brew 安装了 watchman。以下是解决方案的命令列表：
删除守望者（由 brew 安装）：
$ brew install rmtree
$ brew rmtree watchman
$ sudo rm -rf /usr/local/var/run/watchman
手动安装 Watchman v4.7.0（感谢 David）：
$ git clone https://github.com/facebook/watchman.git
$ cd watchman
$ git checkout v4.7.0
$ ./autogen.sh
$ ./configure
$ make
$ sudo make install
chmod 用户的守望者状态目录：
$ chmod 0700 /usr/local/var/run/watchman/<user>-state
在项目文件夹中运行此命令
watchman watch-del-all && npm start --reset-cache
我有一个类似的问题，查看 Watchman 的日志时，每次看到“与 Watchman 的连接丢失”消息时都会发生这些错误。
2016-11-05T03:35:48,401: [listener] Watchman 4.7.0 <no build info set> starting up on Davids-Mac.local
2016-11-05T03:35:48,401: [listener] path /Users/david/Projects/react-native-test is on filesystem type hfs
2016-11-05T03:35:48,402: [listener] root /Users/david/Projects/react-native-test using watcher mechanism fsevents (auto was requested)
2016-11-05T03:35:48,406: [listener] file limit is 2560 kern.maxfilesperproc=10240
2016-11-05T03:35:48,406: [listener] raised file limit to 10240
2016-11-05T03:35:48,407: [listener] Using socket from launchd as listening socket
2016-11-05T03:35:48,934: [io 0x7f8175600ff8 /Users/david/Projects/react-native-test] PERF: {"ru_nvcsw": 0, "ru_nsignals": 0, "ru_msgrcv": 6, "ru_msgsnd": 6, "ru_inblock": 0, "ru_majflt": 0, "ru_nswap": 0, "ru_minflt": 5230, "ru_ixrss": 0, "ru_maxrss": 21405696, "system_time": 0.32367200000000002, "user_time": 0.18271599999999999, "elapsed_time": 0.53129999999999999, "pid": 9867, "ru_idrss": 0, "meta": {"root": {"watcher": "fsevents", "ticks": 2, "number": 1, "case_sensitive": false, "recrawl_count": 0, "path": "/Users/david/Projects/react-native-test"}}, "version": "4.7.0", "ru_oublock": 0, "ru_nivcsw": 112, "start_time": 1478316948.403332, "description": "full-crawl"}
2016-11-05T03:35:48,935: [io 0x7f8175600ff8 /Users/david/Projects/react-native-test] crawl complete
2016-11-05T03:35:49,029: [client=0x7f8176a00038:stm=0x7f8176a00000] Unilateral payload for sub sane-sub {"settled": true}
Terminating due to signal 11 Segmentation fault generated by pid=0 uid=0. address not mapped to object (0x0)
0 watchman 0x0000000105973759 _ZL13crash_handleriP9__siginfoPv + 347
1 libsystem_platform.dylib 0x00007fffa2292bba _sigtramp + 26
2 ??? 0x00007f81756000c0 0x0 + 140193996734656
3 watchman 0x000000010596f9b2 _ZN6detail22estimateSpaceToReserveIPKcJA3_cA28_c8w_stringA2_cPcS6_EEEmmRKT_DpRKT0_ + 109
4 watchman 0x000000010596f815 _ZN8w_string5buildIJPcRA4_KcPS2_RA3_S2_RA28_S2_RS_RA2_S2_RS1_SC_EEES_DpOT_ + 121
5 watchman 0x000000010599b4cb _ZN8watchman3Log3logIJRA28_KcR8w_stringRA2_S2_RPcS8_EEEvNS_8LogLevelEDpOT_ + 183
6 watchman 0x000000010599a6e0 _ZNSt3__114__thread_proxyINS_5tupleIJZL15make_new_clientP15watchman_streamE3$_0EEEEEPvS6_ + 952
7 libsystem_pthread.dylib 0x00007fffa229cabb _pthread_body + 180
8 libsystem_pthread.dylib 0x00007fffa229ca07 _pthread_body + 0
9 libsystem_pthread.dylib 0x00007fffa229c231 thread_start + 13
更新：好的，找到了一个到目前为止似乎可行的解决方案。我完全卸载了 watchman，然后使用以下代码从源代码构建它，这似乎工作正常（任何通过 brew 安装的尝试都会导致上述问题，但这有效）：
$ git clone https://github.com/facebook/watchman.git
$ cd watchman
$ git checkout v4.7.0 # the latest stable release
$ ./autogen.sh
$ ./configure
$ make
$ sudo make install