我正在尝试使用PostgreSQL本地开发Ruby on Rails,所以我正在尝试安装pg gem.在Ubuntu 12.04上.在终端,我输入:
gem install pg -v '0.12.2'
这会引发以下错误:
Building native extensions. This could take a while...
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
/home/troyshu/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
checking for pg_config... yes
Using config values from /usr/bin/pg_config
checking for libpq-fe.h... yes
checking for libpq/libpq-fs.h... yes
checking for pg_config_manual.h... yes
checking for PQconnectdb() in -lpq... no
checking for PQconnectdb() in -llibpq... no
checking for PQconnectdb() in -lms/libpq... no
Can't find the PostgreSQL client library (libpq)
*** extconf.rb …superclass mismatch for class SpecificationPolicy我在尝试安装或升级某些brew 软件包时遇到错误。
例如，更新安装 supabase CLI ( brew install supabase/tap/supabase) 时：
==> Installing supabase from supabase/tap
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems.rb:12: warning: already initialized constant Gem::VERSION
/Library/Ruby/Site/2.6.0/rubygems.rb:11: warning: previous definition of VERSION was here
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/compatibility.rb:14: warning: already initialized constant Gem::RubyGemsVersion
/Library/Ruby/Site/2.6.0/rubygems/compatibility.rb:15: warning: previous definition of RubyGemsVersion was here
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/compatibility.rb:18: warning: already initialized constant Gem::RbConfigPriorities
/Library/Ruby/Site/2.6.0/rubygems/compatibility.rb:18: warning: previous definition of RbConfigPriorities was here
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/compatibility.rb:27: warning: constant Gem::ConfigMap is deprecated
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/compatibility.rb:35: warning: constant Gem::ConfigMap is deprecated
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/defaults.rb:3: warning: already initialized constant …