scons - 告诉 SCons 不要自动创建目录？

Question

我正在尝试让 SCons 检查我需要的 git 存储库(并希望使该存储库保持最新状态)。问题是我必须告诉它 git repo 包含哪些文件才能在构建中使用它们，如果我这样做，SCons 将在尝试克隆它之前创建该 repo。

例如，假设我想克隆 GStreamer，并使用 create-uninstalled-setup.sh脚本(这不是我真正在做的，但它是一个更简单/更快的脚本，它存在同样的问题):

Command(['gstreamer/.git', 'gstreamer/scripts/create-uninstalled-setup.sh'],
    None, 'git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer')
Command('~/gst/git', 'gstreamer/scripts/create-uninstalled-setup.sh',
    'gstreamer/scripts/create-uninstalled-setup.sh')

但它失败了，因为 SCons 在尝试克隆 gstreamer 之前创建了 gstreamer/脚本:

$ scons
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer
fatal: destination path 'gstreamer' already exists and is not an empty directory.
scons: *** [gstreamer/.git] Error 128
scons: building terminated because of errors.
$ ls gstreamer/
scripts

如果我告诉第一个命令它创建了“gstreamer”文件夹，它会创建一个依赖循环:

Command(['gstreamer', 'gstreamer/scripts/create-uninstalled-setup.sh'],
    None, 'git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer')
Command('~/gst/git', 'gstreamer/scripts/create-uninstalled-setup.sh',
    'gstreamer/scripts/create-uninstalled-setup.sh')

$ scons
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
scons: done building targets.

scons: *** Found dependency cycle(s):
gstreamer/scripts -> gstreamer/scripts/create-uninstalled-setup.sh -> gstreamer/scripts
gstreamer/scripts/create-uninstalled-setup.sh -> gstreamer/scripts -> gstreamer/scripts> /create-uninstalled-setup.sh

File "/usr/lib/scons/SCons/Taskmaster.py", line 1019, in cleanup

如果我不告诉第一个命令它创建“create-uninstalled-setup.sh”，它会因为它不存在而感到困惑:

Command(['gstreamer'],
    None, 'git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer')
Command('~/gst/git', 'gstreamer/scripts/create-uninstalled-setup.sh',
    'gstreamer/scripts/create-uninstalled-setup.sh')

$ scons
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
scons: *** [~/gst/git] Source `gstreamer/scripts/create-uninstalled-setup.sh' not found, needed by target `~/gst/git'.
scons: building terminated because of errors.

作为解决方法，我可以 rm -rf我克隆之前的文件夹，但这显然不理想:

Command(['gstreamer/.git', 'gstreamer/scripts/create-uninstalled-setup.sh'], None,
    'rm -rf gstreamer && git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer')
Command('~/gst/git', 'gstreamer/scripts/create-uninstalled-setup.sh',
    'gstreamer/scripts/create-uninstalled-setup.sh')

有没有更好的方法来处理这个问题？

Answer 1

既然没办法告诉git目录确实是空的(即使它有空的子目录)，我们不知道如何告诉 SCons不要自动创建子目录，您可以创建自己的依赖项检查并调用 git clone与 SCons Execute()函数，在任何 SCons 之前执行执行内置依赖项检查，如下所示:

import os.path

setup_file = 'gstreamer/scripts/create-uninstalled-setup.sh'
if not os.path.exists(setup_file)
    Execute('git clone git://anongit.freedesktop.org/git/gstreamer/gstreamer')

Command('~/gst/git', setup_file, setup_file)