安装psycopg2时出错，找不到lssl的库

Question

我跑

sudo pip install psycopg2

我得到了一组输出，看起来像：

cc -DNDEBUG -g -fwrapv -Os .....
.....
cc -DNDEBUG -g -fwrapv -Os .....
.....

最后它说：

ld: library not found for -lssl

clang: error: linker command failed with exit code 1 (use -v to see invocation)

error: command 'cc' failed with exit status 1

----------------------------------------
Cleaning up...
Command /usr/bin/python -c "import setuptools, tokenize;__file__='/private/var/folders/bz/pvj1g9xj16d10pjjgbrfl3fw0000gn/T/pip_build_root/psycopg2/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /var/folders/bz/pvj1g9xj16d10pjjgbrfl3fw0000gn/T/pip-uE3thn-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /private/var/folders/bz/pvj1g9xj16d10pjjgbrfl3fw0000gn/T/pip_build_root/psycopg2
Storing debug log for failure in /Users/Tyler/Library/Logs/pip.log

---

运行easy_install或从源代码执行都会在最后给出相同的错误（关于-lssl的库未找到的部分）

---

运行brew安装（或升级）openssl会产生以下结果

$ brew upgrade openssl
Error: openssl-1.0.1h already installed

有人能帮我吗

Answer 1

对于在macOS Sierra 10.12（或更高版本，最有可能）上寻找此解决方案的任何人：我通过安装命令行工具修复了此问题：

xcode-select --install

在那之后，pip install psycopg2应该会起作用

如果没有，您还可以尝试链接brew的openssl：

env LDFLAGS="-I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib" pip install psycopg2

通过brew安装openssl。请注意brew link openssl --force不再工作：

$ brew link openssl --force                                                                                 17.5s
Warning: Refusing to link: openssl
Linking keg-only openssl means you may end up linking against the insecure,
deprecated system OpenSSL while using the headers from Homebrew's openssl.
Instead, pass the full include/library paths to your compiler e.g.:
  -I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib

正如@macho在下面指出的，如果这仍然不起作用，您可能需要使用pip的--no-cache选项，例如

env LDFLAGS="-I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib" pip --no-cache install psycopg2

记住，如果您构建在ARM/Apple M1 Mac上，请相应地调整这些路径（因为homebrew安装在/opt/homebrew/）；命令如下：

env LDFLAGS="-I/opt/homebrew/opt/openssl/include -L/opt/homebrew/opt/openssl/lib" pip --no-cache install psycopg2

Answer 2

我从brew安装了OpenSSL（brew install openssl）

以下几点对我很有用：

export LDFLAGS="-L/usr/local/opt/openssl/lib"
export CPPFLAGS="-I/usr/local/opt/openssl/include"
pip install psycopg2

Answer 3

使用brew link openssl是危险的，因为它可能会通过将Homebrew的OpenSSL头进行符号链接而弄乱您的系统，而实际的库仍然是系统提供的库，从而导致各种问题。如果您尝试，Homebrew实际上会警告您不要这样做（其他答案表明链接无论如何也解决不了问题）：

$ brew link openssl
Warning: Refusing to link: openssl
Linking keg-only openssl means you may end up linking against the insecure,
deprecated system OpenSSL while using the headers from Homebrew's openssl.
Instead, pass the full include/library paths to your compiler e.g.:
  -I/usr/local/opt/openssl/include -L/usr/local/opt/openssl/lib

以下是您需要使用的pip命令：

$ pip install -r requirements.txt --global-option=build_ext --global-option="-I/usr/local/opt/openssl/include" --global-option="-L/usr/local/opt/openssl/lib"

对于pipenv，我不知道您可以传递给它的任何命令行属性，但是您可以在运行pipenv install之前将上述路径导出为环境变量：

$ export LDFLAGS="-L/usr/local/opt/openssl/lib" export CPPFLAGS="-I/usr/local/opt/openssl/include"
$ pipenv install