「pg」をインストールしようとすると、次のエラーが表示されます。私はレールにかなり慣れていないので、この問題を修正する方法がわかりません。
Davids-MacBook-Air:~ DavidStevenson$ install pg
usage: install [-bCcpSsv] [-B suffix] [-f flags] [-g group] [-m mode]
[-o owner] file1 file2
install [-bCcpSsv] [-B suffix] [-f flags] [-g group] [-m mode]
[-o owner] file1 ... fileN directory
install -d [-v] [-g group] [-m mode] [-o owner] directory ...
Davids-MacBook-Air:~ DavidStevenson$ gem install pg
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/usr/local/rvm/rubies/ruby-1.9.3-p392/bin/ruby extconf.rb
make
compiling gvl_wrappers.c
compiling pg.c
pg.c: In function ‘Init_pg_ext’:
pg.c:384: error: ‘PQPING_OK’ undeclared (first use in this function)
pg.c:384: error: (Each undeclared identifier is reported only once
pg.c:384: error: for each function it appears in.)
pg.c:386: error: ‘PQPING_REJECT’ undeclared (first use in this function)
pg.c:388: error: ‘PQPING_NO_RESPONSE’ undeclared (first use in this function)
pg.c:390: error: ‘PQPING_NO_ATTEMPT’ undeclared (first use in this function)
make: *** [pg.o] Error 1
Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1 for inspection.
Results logged to /usr/local/rvm/gems/ruby-1.9.3-p392/gems/pg-0.15.1/ext/gem_make.out