我正在尝试将我的应用程序推送到Heroku，并将我的gemfile配置为：
group :production do
gem 'pg', '0.18.4'
gem 'rails_12factor', '0.0.2'
gem 'puma'
end
运行bundle install时，我在控制台中收到此错误：
An error occurred while installing pg (0.18.4), and Bundler cannot continue.
Make sure that `gem install pg -v '0.18.4'` succeeds before bundling.
然后当我运行gem install pg -v＆＃39; 0.18.4＆＃39;时，我得到以下内容：
ERROR: While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /Library/Ruby/Gems/2.0.0 directory.
当我运行sudo gem install pg -v '0.18.4'
我得到以下内容：
ERROR: Error installing pg:
ERROR: Failed to build gem native extension.
current directory: /Library/Ruby/Gems/2.0.0/gems/pg-0.18.4/ext
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby -r ./siteconf20160125-5501-ugsd1s.rb extconf.rb
checking for pg_config... yes
Using config values from /usr/local/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 failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers. Check the mkmf.log file for more details. You may
need configuration options.
更新
我重新安装了RVM和rails，现在当我运行gem install pg -v＆＃39; 0.18.4＆＃39;时，它运行成功：
Successfully installed pg-0.18.4
Parsing documentation for pg-0.18.4
Done installing documentation for pg after 3 seconds
1 gem installed
但是当运行bundle install时，我得到了这个：
Installing pg 0.18.4 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
current directory: /Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/gems/pg-0.18.4/ext
/Users/benwong/.rvm/rubies/ruby-2.2.1/bin/ruby -r ./siteconf20160126-44660-1ufenyc.rb extconf.rb --with-pg-config=/Applications/Postgres.app/Contents/MacOS/bin/pg_config
Using config values from /Applications/Postgres.app/Contents/MacOS/bin/pg_config
sh: /Applications/Postgres.app/Contents/MacOS/bin/pg_config: No such file or directory
sh: /Applications/Postgres.app/Contents/MacOS/bin/pg_config: No such file or directory
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... yes
checking for PQconnectionUsedPassword()... yes
checking for PQisthreadsafe()... yes
checking for PQprepare()... yes
checking for PQexecParams()... yes
checking for PQescapeString()... yes
checking for PQescapeStringConn()... yes
checking for PQescapeLiteral()... yes
checking for PQescapeIdentifier()... yes
checking for PQgetCancel()... yes
checking for lo_create()... yes
checking for pg_encoding_to_char()... yes
checking for pg_char_to_encoding()... yes
checking for PQsetClientEncoding()... yes
checking for PQlibVersion()... yes
checking for PQping()... yes
checking for PQsetSingleRowMode()... yes
checking for PQconninfo()... yes
checking for rb_encdb_alias()... yes
checking for rb_enc_alias()... yes
checking for rb_thread_call_without_gvl()... yes
checking for rb_thread_call_with_gvl()... yes
checking for rb_thread_fd_select()... yes
checking for rb_w32_wrap_io_handle()... no
checking for rb_str_modify_expand()... yes
checking for rb_hash_dup()... yes
checking for PGRES_COPY_BOTH in libpq-fe.h... yes
checking for PGRES_SINGLE_TUPLE in libpq-fe.h... yes
checking for PG_DIAG_TABLE_NAME in libpq-fe.h... yes
checking for struct pgNotify.extra in libpq-fe.h... yes
checking for unistd.h... yes
checking for inttypes.h... yes
checking for ruby/st.h... yes
checking for C99 variable length arrays... yes
creating extconf.h
creating Makefile
To see why this extension failed to compile, please check the mkmf.log which can be found here:
/Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/pg-0.18.4/mkmf.log
current directory: /Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/gems/pg-0.18.4/ext
make "DESTDIR=" clean
current directory: /Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/gems/pg-0.18.4/ext
make "DESTDIR="
compiling gvl_wrappers.c
compiling pg.c
compiling pg_binary_decoder.c
compiling pg_binary_encoder.c
compiling pg_coder.c
compiling pg_connection.c
pg_connection.c:2394:3: warning: implicit declaration of function 'gettimeofday' is invalid in C99 [-Wimplicit-function-declaration]
gettimeofday(&currtime, NULL);
^
1 warning generated.
compiling pg_copy_coder.c
compiling pg_errors.c
compiling pg_result.c
compiling pg_text_decoder.c
compiling pg_text_encoder.c
compiling pg_type_map.c
compiling pg_type_map_all_strings.c
compiling pg_type_map_by_class.c
compiling pg_type_map_by_column.c
compiling pg_type_map_by_mri_type.c
compiling pg_type_map_by_oid.c
compiling pg_type_map_in_ruby.c
compiling util.c
linking shared-object pg_ext.bundle
ld: warning: directory not found for option '-L/Users/haven/.sm/pkg/active/lib'
ld: file not found: dynamic_lookup
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [pg_ext.bundle] Error 1
make failed, exit code 2
Gem files will remain installed in /Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/gems/p
g-0.18.4 for inspection.
Results logged to /Users/benwong/Desktop/ruby/rails_projects/blog2/vendor/bundle/ruby/2.2.0/extensions/x86_64-darwin-14/2.2.0-static/pg-0.18.4/gem_make.out
Using puma 2.15.3
Using rails_serve_static_assets 0.0.4
Using rails_stdout_logging 0.0.4
Using sass 3.4.21
Using tilt 2.0.2
Using spring 1.6.2
Using rdoc 4.2.1
Using tzinfo 1.2.2
Using nokogiri 1.6.7.2
Using rack-test 0.6.3
Using warden 1.2.4
Using mail 2.6.3
Using binding_of_caller 0.7.2
Using coffee-script 2.4.1
Using uglifier 2.7.2
Using sprockets 3.5.2
An error occurred while installing pg (0.18.4), and Bundler cannot continue.
Make sure that `gem install pg -v '0.18.4'` succeeds before bundling.
答案 0 :(得分：0)
您需要安装PostgreSQL才能安装pg gem。还需要配置PATH。 您可以使用http://postgresapp.com/在Mac上轻松安装PostgreSQL。并使用它来配置PATH：http://postgresapp.com/documentation/cli-tools.html
答案 1 :(得分：0)
尝试一下对我有用，它必须具有所有psql依赖项，这样它才能起作用
sudo apt-get install -y libpq-dev build-essential postgresql-server-dev-all libpgsql-ruby postgresql ruby-dev && gem install pg
答案 2 :(得分：-1)
很多时候你可以在安装宝石时找到答案，因为互联网很慢......你确定不是吗？你又试过了吗？你的第二个片段是线索......解释其余部分。