Pylint在OS X的Emacs GUI中不工作；从命令行正常

Question

从命令行运行时（比如输入 emacs filename.py），flymake 和 pylint 可以很好地配合使用，错误会被正确高亮显示。（不过因为是在文本模式下，我无法悬停查看错误的详细信息。）

但是在图形界面（Carbon Emacs）中运行时，Flymake 会立即返回，文件的第一行会被标记为错误 "in <module>"。即使是一个简单的 "Hello World" 脚本，第一行也会显示错误。我希望在图形界面模式下能正常工作，这样我就可以用鼠标导航（我知道，我知道），并使用工具提示查看 pylint 报告的错误详情。

我通过 "easy_install pylint" 安装了 pylint，pylint 和 epylint 的脚本在 "~/py/scripts" 目录下。我把这个目录添加到了我的 .bashrc 的 PATH 中：

export PATH=$PATH:~/py/scripts

（我的 .profile 是指向 .bashrc 的符号链接。）

我发现 Emacs-GUI 没有加载我 .bashrc 中的路径，所以我创建了一个 ~/.MacOSX/environment.plist 文件，设置了 PATH 变量，内容是我在终端中看到的完整 PATH。

现在在 Emacs-GUI 中，"(getenv "PATH")" 的输出看起来是正确的：

"/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/git/bin:/usr/X11/bin:/Users/schof/py/scripts:/usr/X11R6/bin"

同样，"C-h v exec-path" 的输出也看起来正确：

("/usr/bin" "/bin" "/usr/sbin" "/sbin" "/usr/local/bin" "/usr/local/git/bin" "/usr/X11/bin" "/Users/schof/py/scripts" "/Applications/Emacs.app/Contents/MacOS/libexec" "/Applications/Emacs.app/Contents/MacOS/bin" "/usr/X11R6/bin")

但这让我没有其他想法来解决这个问题。我并不是 Emacs 的专家，所以可能我遗漏了一些明显的东西；如果需要更多细节，请随时问我。

操作系统是 OS X 10.6.7；Carbon Emacs 22.3.1；pylint 0.23.0。

Flymake / Pylint 的代码在 .emacs 中：

  (when (load "flymake" t)
      (defun flymake-pylint-init ()
        (let* ((temp-file (flymake-init-create-temp-buffer-copy
                           'flymake-create-temp-inplace))
           (local-file (file-relative-name
                        temp-file
                        (file-name-directory buffer-file-name))))
          (list "epylint" (list local-file))))

      (add-to-list 'flymake-allowed-file-name-masks
               '("\\.py\\'" flymake-pylint-init)))


;; Auto-start flymake-mode when you go into python-mode
(add-hook 'python-mode-hook
          '(lambda ()
                   (setq python-indent 4)
                   (flymake-mode)))

更新 2011-04-05，回应 @sanityinc 的回答：

flymake 在 *messages* 中的详细输出级别为 3：（这对我来说并没有让问题的来源变得明显。）

starting syntax check as new-line has been seen
flymake is running: nil
file /Users/schof/pytest.py, init=flymake-pylint-init [3 times]
create-temp-inplace: file=/Users/schof/pytest.py temp=/Users/schof/pytest_flymake.py
saved buffer pytest.py in file /Users/schof/pytest_flymake.py
started process 3221, command=(epylint pytest_flymake.py), dir=/Users/schof/
received 704 byte(s) of output from process 3221
file /Users/schof/pytest.py, init=flymake-pylint-init
parsed 'Traceback (most recent call last):', no line-err-info
parse line: file-idx=2 line-idx=3 file=/Users/schof/py/scripts/epylint line=4 text=in <module>
get-real-file-name: file-name=/Users/schof/py/scripts/epylint real-name=~/py/scripts/epylint
parsed '  File "/Users/schof/py/scripts/epylint", line 4, in <module>', got line-err-info
parsed '    import pkg_resources', no line-err-info
parse line: file-idx=2 line-idx=3 file=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py line=2556 text=in <module>
get-real-file-name: file-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py real-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py
parsed '  File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py", line 2556, in <module>', got line-err-info
parsed '    working_set.require(__requires__)', no line-err-info
parse line: file-idx=2 line-idx=3 file=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py line=620 text=in require
get-real-file-name: file-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py real-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py
parsed '  File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py", line 620, in require', got line-err-info
parsed '    needed = self.resolve(parse_requirements(requirements))', no line-err-info
parse line: file-idx=2 line-idx=3 file=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py line=518 text=in resolve
get-real-file-name: file-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py real-name=/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py
parsed '  File "/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.py", line 518, in resolve', got line-err-info
parsed '    raise DistributionNotFound(req)  # XXX put more info here', no line-err-info
parsed 'pkg_resources.DistributionNotFound: pylint==0.23.0', no line-err-info
file /Users/schof/pytest.py, init=flymake-pylint-init
process 3221 exited with code 1
cleaning up using flymake-simple-cleanup
deleted file /Users/schof/pytest_flymake.py
created an overlay at (1-18)
pytest.py: 4 error(s), 0 warning(s) in 0.47 second(s)

为了比较，这里是从 Emacs 文本模式 运行时 flymake 详细输出级别 3 的结果。"hello world" 文件通过了所有 pylint 测试。

starting syntax check as new-line has been seen                                                                         
flymake is running: nil                                                                                                 
file /Users/schof/pytest.py, init=flymake-pylint-init [3 times]                                                         
create-temp-inplace: file=/Users/schof/pytest.py temp=/Users/schof/pytest_flymake.py                                    
saved buffer pytest.py in file /Users/schof/pytest_flymake.py                                                           
started process 3395, command=(epylint pytest_flymake.py), dir=/Users/schof/                                            
file /Users/schof/pytest.py, init=flymake-pylint-init                                                                   
process 3395 exited with code 0                                                                                         
cleaning up using flymake-simple-cleanup                                                                                
deleted file /Users/schof/pytest_flymake.py                                                                             
pytest.py: 0 error(s), 0 warning(s) in 0.30 second(s) 

Answer 1

为了更清楚地了解问题出在哪里，可以提高flymake的日志级别，然后查看*messages*里的内容：

(setq flymake-log-level 3)

如果没有这些信息，我也不敢随便猜测可能的问题。

顺便提一下，有一个方法可以避免使用environment.plist；你可以让Emacs询问你常用的shell来获取你喜欢的PATH：

(defun set-exec-path-from-shell-PATH ()
  (let ((path-from-shell (replace-regexp-in-string
                          "[ \t\n]*$"
                          ""
                          (shell-command-to-string "$SHELL --login -i -c 'echo $PATH'"))))
    (setenv "PATH" path-from-shell)
    (setq exec-path (split-string path-from-shell path-separator))))

(when (and window-system (eq system-type 'darwin))
  ;; When started from Emacs.app or similar, ensure $PATH
  ;; is the same the user would see in Terminal.app
  (set-exec-path-from-shell-PATH))

（这段代码来自于我的Emacs配置，里面有很多flymake的代码，包括一个使用pyflakes的python配置，你可以去看看。）

更新：现在你已经添加了详细输出，我发现你的~/py/epylint程序找不到pkg_resources，这说明PYTHONPATH可能设置错了。所以，试试用上面提到的方法变个花样：

(defun setenv-from-shell (varname)
  (setenv varname (replace-regexp-in-string
                   "[ \t\n]*$"
                   ""
                   (shell-command-to-string (concat "$SHELL --login -i -c 'echo $" varname "'")))))

(setenv-from-shell "PYTHONPATH")