不管怎么做，PostgreSQL都无法运行
我已经无法计算我第几次 PostgreSQL 没有运行了。
我没反省，就算多次没有运行，这样真是太蠢了，所以这次一定要记下来。
这是我自己完全设下的陷阱，自己反而落入其中，所以我觉得这个故事并不值得参考。
像往常一样使用 brew 进行安装，然后将长长的日志粘贴到终端上。
$ brew install postgresql
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> New Formulae
fasttext
==> Updated Formulae
pcre2 ✔ hugo istioctl lz4
gmic ios-webkit-debug-proxy libuv zstd
==> Installing dependencies for postgresql: readline
==> Installing postgresql dependency: readline
==> Downloading https://homebrew.bintray.com/bottles/readline-8.0.0.mojave.bottle.tar.gz
Already downloaded: /Users/ninjaninja/Library/Caches/Homebrew/downloads/9857a88bdb1a8ec96b986e99084ea823541d357d451a70a028e7c30410f918e9--readline-8.0.0.mojave.bottle.tar.gz
==> Pouring readline-8.0.0.mojave.bottle.tar.gz
==> Caveats
readline is keg-only, which means it was not symlinked into /usr/local,
because macOS provides the BSD libedit library, which shadows libreadline.
In order to prevent conflicts when programs look for libreadline we are
defaulting this GNU Readline installation to keg-only.
For compilers to find readline you may need to set:
export LDFLAGS="-L/usr/local/opt/readline/lib"
export CPPFLAGS="-I/usr/local/opt/readline/include"
For pkg-config to find readline you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/readline/lib/pkgconfig"
==> Summary
? /usr/local/Cellar/readline/8.0.0: 48 files, 1.5MB
==> Installing postgresql
==> Downloading https://homebrew.bintray.com/bottles/postgresql-11.2.mojave.bottle.tar.gz
Already downloaded: /Users/ninjaninja/Library/Caches/Homebrew/downloads/991d29978b1e0603895b59851c553e41370fefedbb67797b6078ead33bccdba2--postgresql-11.2.mojave.bottle.tar.gz
==> Pouring postgresql-11.2.mojave.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink include/ecpg_config.h
/usr/local/include is not writable.
You can try again using:
brew link postgresql
==> Caveats
To migrate existing data from a previous major version of PostgreSQL run:
brew postgresql-upgrade-database
To have launchd start postgresql now and restart at login:
brew services start postgresql
Or, if you don't want/need a background service you can just run:
pg_ctl -D /usr/local/var/postgres start
==> Summary
? /usr/local/Cellar/postgresql/11.2: 3,186 files, 35.4MB
==> Caveats
==> readline
readline is keg-only, which means it was not symlinked into /usr/local,
because macOS provides the BSD libedit library, which shadows libreadline.
In order to prevent conflicts when programs look for libreadline we are
defaulting this GNU Readline installation to keg-only.
For compilers to find readline you may need to set:
export LDFLAGS="-L/usr/local/opt/readline/lib"
export CPPFLAGS="-I/usr/local/opt/readline/include"
For pkg-config to find readline you may need to set:
export PKG_CONFIG_PATH="/usr/local/opt/readline/lib/pkgconfig"
==> postgresql
To migrate existing data from a previous major version of PostgreSQL run:
brew postgresql-upgrade-database
To have launchd start postgresql now and restart at login:
brew services start postgresql
Or, if you don't want/need a background service you can just run:
pg_ctl -D /usr/local/var/postgres start
按照日志所述，设置用于readline的环境变量。
$ echo -e "export LDFLAGS=\"-L/usr/local/opt/readline/lib\"\nexport CPPFLAGS=\"-I/usr/local/opt/readline/include\"\nexport PKG_CONFIG_PATH=\"/usr/local/opt/readline/lib/pkgconfig\"" >> ~/.bash_profile
$ source ~/.bash_profile
通过 brew services 启动 postgres。
$ brew services start postgresql
==> Successfully started `postgresql` (label: homebrew.mxcl.postgresql)
$ brew services list
Name Status User Plist
mysql@5.6 stopped
postgresql started ninjaninja /Users/ninjaninja/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
redis started ninjaninja /Users/ninjaninja/Library/LaunchAgents/homebrew.mxcl.redis.plist
PostgreSQL 已经启动了（・｀ω・´）
$ psql
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
好的，出错了。又是这个常见的错误。每次都会出现，真是没反省呢。我真是个笨蛋。我们来解决吧。
嗯嗯。
当/主机以/开头时，会使用Unix域套接字进行连接。
那么解决方法是，在命令中加入 –host localhost 选项，强制通过TCP/IP连接。我在 Stackoverflow 上学到的。
$ psql -hlocalhost
psql: FATAL: role "ninjaninja" does not exist
啊，要不用户输入的话。
$ psql -hlocalhost -Upostgres
dyld: lazy symbol binding failed: Symbol not found: _PQsetErrorContextVisibility
Referenced from: /usr/local/opt/postgresql/bin/psql
Expected in: /usr/lib/libpq.5.dylib
dyld: Symbol not found: _PQsetErrorContextVisibility
Referenced from: /usr/local/opt/postgresql/bin/psql
Expected in: /usr/lib/libpq.5.dylib
Abort trap: 6
这个错误是什么呢？(；ﾞﾟ’ωﾟ’）：
问了世界上的朋友，完全找不到答案。这是怎么回事呀。然后我再次查看安装时的日志。
==> Pouring postgresql-11.2.mojave.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink include/ecpg_config.h
/usr/local/include is not writable.
出错了啊。好好注意一下。
/usr/local/include不可写。
唔。家里环境里没有/usr/local/include，怎么办啊?!
这是因为我之前的文章引起的问题呢:(；ﾞﾟ’ωﾟ’）:
在这种情况下，我将 /usr/local/include 移动到了 /usr/local/include_old。
不要恢复/usr/local/include，我们会重新创建。这样会导致rbenv无法正常运行。
$ sudo mkdir /usr/local/include
$ sudo chown ninjaninja:admin /usr/local/include
然后重新安装PostgreSQL。
$ brew uninstall postgresql
Uninstalling /usr/local/Cellar/postgresql/11.2... (3,186 files, 35.4MB)
$ brew install postgresql
==> Downloading https://homebrew.bintray.com/bottles/postgresql-11.2.mojave.bottle.tar.gz
Already downloaded: /Users/ninjaninja/Library/Caches/Homebrew/downloads/991d29978b1e0603895b59851c553e41370fefedbb67797b6078ead33bccdba2--postgresql-11.2.mojave.bottle.tar.gz
==> Pouring postgresql-11.2.mojave.bottle.tar.gz
==> Caveats
To migrate existing data from a previous major version of PostgreSQL run:
brew postgresql-upgrade-database
To have launchd start postgresql now and restart at login:
brew services start postgresql
Or, if you don't want/need a background service you can just run:
pg_ctl -D /usr/local/var/postgres start
==> Summary
? /usr/local/Cellar/postgresql/11.2: 3,186 files, 35.4MB
嗨，这次一定没有错误。
$ psql -hlocalhost -Upostgres
psql (11.2)
Type "help" for help.
postgres=#
终于成功访问到了，我真的觉得自己太傻了。
