无法使用 rails 安装 pg gem

Question

我有这个可怕的错误：

An error occurred while installing pg (1.2.3), and Bundler cannot continue.
Make sure that `gem install pg -v '1.2.3' --source 'https://rubygems.org/'` succeeds before bundling.

我的工作大大耽搁了。在此错误出现之前：

compiling gvl_wrappers.c
compiling pg.c
compiling pg_binary_decoder.c
compiling pg_binary_encoder.c
compiling pg_coder.c
pg_coder.c:216:34: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        res = this->dec_func(this, val, RSTRING_LEN(argv[0]), tuple, field, ENCODING_GET(argv[0]));
              ~~~~                      ^~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1007:6: note: expanded from macro 'RSTRING_LEN'
     RSTRING_EMBED_LEN(str) : \
     ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1003:6: note: expanded from macro 'RSTRING_EMBED_LEN'
     (long)((RBASIC(str)->flags >> RSTRING_EMBED_LEN_SHIFT) & \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_coder.c:216:34: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        res = this->dec_func(this, val, RSTRING_LEN(argv[0]), tuple, field, ENCODING_GET(argv[0]));
              ~~~~                      ^~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1008:28: note: expanded from macro 'RSTRING_LEN'
     RSTRING(str)->as.heap.len)
     ~~~~~~~~~~~~~~~~~~~~~~^~~
2 warnings generated.
compiling pg_connection.c
compiling pg_copy_coder.c
pg_copy_coder.c:228:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                                        strlen = RSTRING_LEN(subint);
                                               ~ ^~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1007:6: note: expanded from macro 'RSTRING_LEN'
     RSTRING_EMBED_LEN(str) : \
     ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1003:6: note: expanded from macro 'RSTRING_EMBED_LEN'
     (long)((RBASIC(str)->flags >> RSTRING_EMBED_LEN_SHIFT) & \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_copy_coder.c:228:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                                        strlen = RSTRING_LEN(subint);
                                               ~ ^~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1008:28: note: expanded from macro 'RSTRING_LEN'
     RSTRING(str)->as.heap.len)
     ~~~~~~~~~~~~~~~~~~~~~~^~~

我想知道这些错误是从哪里来的，在我看来它无法转换某些东西，也许是在我的 rails 数据库结构中？

pg_copy_coder.c:534:23: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                input_len = end_ptr - start_ptr;
                          ~ ~~~~~~~~^~~~~~~~~~~
3 warnings generated.
compiling pg_errors.c
compiling pg_record_coder.c
pg_record_coder.c:196:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                                        strlen = RSTRING_LEN(subint);
                                               ~ ^~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1007:6: note: expanded from macro 'RSTRING_LEN'
     RSTRING_EMBED_LEN(str) : \
     ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1003:6: note: expanded from macro 'RSTRING_EMBED_LEN'
     (long)((RBASIC(str)->flags >> RSTRING_EMBED_LEN_SHIFT) & \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_record_coder.c:196:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                                        strlen = RSTRING_LEN(subint);
                                               ~ ^~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1008:28: note: expanded from macro 'RSTRING_LEN'
     RSTRING(str)->as.heap.len)
     ~~~~~~~~~~~~~~~~~~~~~~^~~
2 warnings generated.
compiling pg_result.c
compiling pg_text_decoder.c
compiling pg_text_encoder.c

再次出现同样的错误，转换丢失阻止它安装 postgresql：

pg_text_encoder.c:194:14: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                        len = out - start;
                            ~ ~~~~^~~~~~~
pg_text_encoder.c:406:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                return optr - out;
                ~~~~~~ ~~~~~^~~~~
pg_text_encoder.c:410:12: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
                return 2 + RSTRING_LEN(*intermediate) * 2;
                ~~~~~~ ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_text_encoder.c:617:13: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        nr_elems = RARRAY_LEN(value);
                 ~ ^~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1070:23: note: expanded from macro 'RARRAY_LEN'
#define RARRAY_LEN(a) rb_array_len(a)
                      ^~~~~~~~~~~~~~~
4 warnings generated.
compiling pg_tuple.c
pg_tuple.c:482:15: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        num_fields = RARRAY_LEN(values);
                   ~ ^~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1070:23: note: expanded from macro 'RARRAY_LEN'
#define RARRAY_LEN(a) rb_array_len(a)
                      ^~~~~~~~~~~~~~~
1 warning generated.
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
pg_type_map_by_column.c:161:52: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        return dec_func( p_coder, RSTRING_PTR(field_str), RSTRING_LEN(field_str), 0, fieldno, enc_idx );
               ~~~~~~~~                                   ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1007:6: note: expanded from macro 'RSTRING_LEN'
     RSTRING_EMBED_LEN(str) : \
     ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1003:6: note: expanded from macro 'RSTRING_EMBED_LEN'
     (long)((RBASIC(str)->flags >> RSTRING_EMBED_LEN_SHIFT) & \
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_type_map_by_column.c:161:52: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        return dec_func( p_coder, RSTRING_PTR(field_str), RSTRING_LEN(field_str), 0, fieldno, enc_idx );
               ~~~~~~~~                                   ^~~~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1008:28: note: expanded from macro 'RSTRING_LEN'
     RSTRING(str)->as.heap.len)
     ~~~~~~~~~~~~~~~~~~~~~~^~~
pg_type_map_by_column.c:230:17: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        conv_ary_len = RARRAY_LEN(conv_ary);
                     ~ ^~~~~~~~~~~~~~~~~~~~
/Users/EvanRoberts/.rvm/rubies/ruby-2.7.0/include/ruby-2.7.0/ruby/ruby.h:1070:23: note: expanded from macro 'RARRAY_LEN'
#define RARRAY_LEN(a) rb_array_len(a)
                      ^~~~~~~~~~~~~~~
3 warnings generated.
compiling pg_type_map_by_mri_type.c
compiling pg_type_map_by_oid.c
compiling pg_type_map_in_ruby.c
compiling pg_util.c
pg_util.c:119:24: warning: implicit conversion loses integer precision: 'long' to 'int' [-Wshorten-64-to-32]
        return (char*)out_ptr - out;
        ~~~~~~ ~~~~~~~~~~~~~~~^~~~~
1 warning generated.
linking shared-object pg_ext.bundle
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

我不知道从哪里开始，我在 Google 上搜索过，Stackoverflow 搜索了“隐式转换失去整数精度”，但没有可以使用的实际结果。我认为sql可能无法将我的数据库从rails的标准数据库管理转换为sql，也许？有人可以帮忙吗

Answer 1

这些都只是警告。您的错误在底部：

ld: file not found: dynamic_lookup

您的系统配置中缺少某些内容，要么是 xcode 工具（sudo xcode-select -s /Library/Developer/CommandLineTools 通常是修复该问题的调用），要么您需要根据 this answer 配置 pg_config 的路径。