Question

我在使用pip install安装时遇到了很多问题。

大多数pip安装失败。我将在这里给出几个片段来演示，但几乎每个pip安装都以类似的方式失败。我尝试了一些简单的事情，比如升级pip但到目前为止没有运气。

我正在跑步：

 pip 8.1.2 from /Library/Python/2.7/site-packages (python 2.7)
 OSX 10.10.4 Yosemite

例如，如果我尝试安装诸如网络抓取库之类的模块，那么事情似乎开始很好：


pip install scrapy

Collecting scrapy
/Library/Python/2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#snimissingwarning.
  SNIMissingWarning
/Library/Python/2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
  Using cached Scrapy-1.1.0-py2.py3-none-any.whl
Requirement already satisfied (use --upgrade to upgrade): pyOpenSSL in /System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python (from scrapy)
Requirement already satisfied (use --upgrade to upgrade): cssselect>=0.9 in /Library/Python/2.7/site-packages (from scrapy)
Requirement already satisfied (use --upgrade to upgrade): PyDispatcher>=2.0.5 in /Library/Python/2.7/site-packages (from scrapy)
Collecting parsel>=0.9.3 (from scrapy)
  Using cached parsel-1.0.2-py2.py3-none-any.whl
Collecting lxml (from scrapy)
  Using cached lxml-3.6.0.tar.gz

但后来结果相同：


      Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?

细节：


cc -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DTRACE -arch x86_64 -arch i386 -pipe -I/Applications/MAMP/Library/include -I/Applications/MAMP/Library/include/libxml2 -Isrc/lxml/includes -I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c src/lxml/lxml.etree.c -o build/temp.macosx-10.10-intel-2.7/src/lxml/lxml.etree.o -w -flat_namespace
  In file included from src/lxml/lxml.etree.c:320:
  src/lxml/includes/etree_defs.h:14:10: fatal error: 'libxml/xmlversion.h' file not found
  #include "libxml/xmlversion.h"
           ^
  1 error generated.
  Compile failed: command 'cc' failed with exit status 1
  creating var
  creating var/folders
  creating var/folders/y4
  creating var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2
  creating var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2/T
  cc -I/Applications/MAMP/Library/include -I/Applications/MAMP/Library/include/libxml2 -I/usr/include/libxml2 -c /var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2/T/xmlXPathInitFfTVls.c -o var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2/T/xmlXPathInitFfTVls.o
  /var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2/T/xmlXPathInitFfTVls.c:2:1: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
  main (int argc, char **argv) {
  ^
  1 warning generated.
  cc var/folders/y4/5myrk5lj12990054wgpw6hmxrhplv2/T/xmlXPathInitFfTVls.o -L/Applications/MAMP/Library/lib -lxml2 -o a.out
  ld: warning: ignoring file /Applications/MAMP/Library/lib/libxml2.dylib, missing required architecture x86_64 in file /Applications/MAMP/Library/lib/libxml2.dylib (2 slices)
  Undefined symbols for architecture x86_64:
    "_xmlXPathInit", referenced from:
        _main in xmlXPathInitFfTVls.o
  ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  *********************************************************************************
  Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?
  Perhaps try: xcode-select --install
  *********************************************************************************
  error: command 'cc' failed with exit status 1

  ----------------------------------------
  Failed building wheel for lxml

Answer 1

好吧我不知道为什么会这样，但这很有效。

我去了这里： https://www.continuum.io/downloads

我安装了Anaconda for OSX python 2.7版。

我打开了一个新的终端窗口，确认安装了conda然后再次尝试使用pip。这一切都是固定的。不知道为什么会这样，但它对我有用。

pip install上的libxml2错误

1 个答案: