這幾天在裝 mysql2 gems 時發生如下的錯誤
Using mysql_config at /usr/local/bin/mysql_config
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checking for mysql.h... yes
checking for errmsg.h... yes
checking for mysqld_error.h... yes
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Don't know how to set rpath on your system, if MySQL libraries are not in path mysql2 may not load
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Setting libpath to /usr/local/Cellar/mysql/5.6.25/lib
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creating Makefile
make "DESTDIR=" clean
make "DESTDIR="
compiling client.c
compiling infile.c
compiling mysql2_ext.c
compiling result.c
linking shared-object mysql2/mysql2.bundle
ld: warning: directory not found for option '-L/Users/travis/.sm/pkg/active/lib'
ld: library not found for -lssl
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [mysql2.bundle] Error 1
make failed, exit code 2
原因主要是 ld: library not found for -lssl
通常是 openssl 未安裝或路徑設定有誤
可以先試著重裝 openssl ，必且重新設定對應的環境變數
brew install openssl
export LIBRARY_PATH=$LIBRARY_PATH:/usr/local/opt/openssl/lib/
重新安裝 mysql2 gem 應該就正常囉！
參考資料: