Virtualenv激活脚本无法在带有-euo设置的bash脚本中运行 [英] Virtualenv activate script won't run in bash script with set -euo
问题描述
我正在尝试创建一个bash脚本来激活virtualenv，pip安装requirements.txt并继续.这将是我的init.sh脚本，供以后使用.
I am trying to create a bash script that activates the virtualenv, pip installs the requirements.txt and continue. This will be my init.sh script for later business.
#!/usr/bin/env bash
set -euo pipefail
. ${DIR}/scripts-venv/bin/activate
pip install -r requirements.txt
其中$ {DIR}设置为包含virtualenv的目录.看来问题出在上述 set -euo 上，根据一些样式指南，这是推荐开始使用bash脚本的起点.更具体地说，它的 u 选项-交互式，产生错误/scripts-venv/bin/activate:第57行:PS1:未绑定变量.我可以删除它，但是只是想知道为什么会这样.谢谢
where ${DIR} is set to my directory that contains the virtualenv. It seems the issue lies in the above set -euo which is the recommended start to bash scripts according to some style guides. More specifically, its the u option - interactive that gives the error /scripts-venv/bin/activate: line 57: PS1: unbound variable. I can remove it, but was just wondering why this is happening.
Thanks
推荐答案
如果可以更新，则virtualenv> = 16.2不再有未设置PS1的错误
如果您能够更新 virtualenv 库，则将发现此库现已修复.它已在 pypa/virtualenv/pull/922 中进行了修复，该版本已包含在16.2中.里程碑.
If you can update, virtualenv>=16.2 no longer has errors from PS1 not being set
If you are able to update the virtualenv library you will find this is now fixed. It was fixed in pypa/virtualenv/pull/922, which was included in the 16.2 milestone.
$ PS1 是显示在bash提示中 $ 前面的文本. -u 表示对未绑定变量的引用是错误的.由于/scripts-venv/bin/activate 是指 $ PS1 ，并且由于在交互式shell上没有提示，因此这是一个未绑定的变量，而 -u 导致脚本失败.
$PS1 is the text that appears in front of the $ in your bash prompt. -u says that references to unbound variables are errors. Since /scripts-venv/bin/activate refers to $PS1 and since there's no prompt on an interactive shell then this is an unbound variable and -u causes the script to fail.
也许有帮助:
https://unix.stackexchange.com/questions/170493/login-non-login-and-active-non-interactive-shells
调用脚本时，运行该脚本的外壳没有提示.现在，在第57行的 bin/activate 内部查看:
When you call a script, the shell that runs that script doesn't have a prompt. Now, look inside bin/activate, line 57:
_OLD_VIRTUAL_PS1="$PS1"
您会看到将对 $ PS1 进行评估，并且由于设置了 -u ，因此脚本无法继续，因为 -u 表示尝试对未设置的变量进行参数评估是错误的.
You can see that $PS1 is going to get evaluated, and because you have -u set, your script can't continue because -u says an attempt to do parameter evaluation of an unset variable is an error.
以下是您的一些选择:
第57行:
- _OLD_VIRTUAL_PS1="$PS1"
+ _OLD_VIRTUAL_PS1="${PS1:-}"
第61行:
- PS1="(`basename \"$VIRTUAL_ENV\"`) $PS1"
+ PS1="(`basename \"$VIRTUAL_ENV\"`) ${PS1:-}"
:-语法使扩展默认为空字符串而不是未绑定，因此没有错误.但这是繁重的工作，因为您搞砸了 virtualenv 创建的代码.
The :- syntax causes the expansion to default to an empty string instead of unbound so there's no error. But this is heavy handed because you're messing with the virtualenv created code.
在 activate 脚本期间删除 -u 可能更好.
Probably its better just to remove -u during the activate script.
尝试使用此脚本，了解我的意思:
Try this script, to see what I mean:
#!/bin/bash
set -eux
echo "Testing vitualenv"
set +u
. venv/bin/activate
set -u
echo "Test complete $?"
通过在激活过程中关闭 -u ，然后再次将其重新打开，您可以解决virtualenv的尴尬(如果您不想修复它).
By turning off -u during activate and then turning it back on again you can just work around the virtualenv awkwardness (if you don't want to fix it).
只需更新virtualenv，使其版本> = 16.2. pip install --upgrade virtualenv
Just update virtualenv so it is version >= 16.2. pip install --upgrade virtualenv
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