bashcov-如果python调用子程序,则不起作用

我已经安装了bashcov。。为了测量一堆bash脚本中的代码覆盖率:

$ bash --version                                                                                                      GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu)
...
$ bundle exec bashcov --version
bashcov 1.8.2

这完全按预期工作:

$ cat main.sh 
#! /usr/bin/env bash

set -e

if [[ "$1" == "" ]]
then
  echo no args
else
  echo args
fi

./sub.sh
$ cat sub.sh 
#! /usr/bin/env bash

set -e

if [[ "$1" == "" ]]
then
  echo no args in subprogram
else
  echo args in subprogram
fi
$ bundle exec bashcov ./main.sh 
no args
no args in subprogram
Run completed using bashcov 1.8.2 with Bash 5.0, Ruby 2.7.0, and SimpleCov 0.15.1.
Coverage report generated for /bin/bash ./main.sh to ~/bashcov/coverage. 7 / 9 LOC (77.78%) covered.

我得到了这些html报告:

因此,它完全可以调用另一个bash程序并测量其覆盖率。

然而

当我试图将python程序放在中间时,事情并不像我希望的那样工作:

$ cat main.sh 
#! /usr/bin/env bash

set -e

if [[ "$1" == "" ]]
then
  echo no args
else
  echo args
fi

python3 -u sub.py

$ cat sub.py 
import subprocess

print("running subprograms")

subprocess.run(["./sub.sh"])
$ # and leave sub.sh the same as above
$ bundle exec bashcov ./main.sh 
no args
running subprograms
bash: BASH_XTRACEFD: 8: invalid value for trace file descriptor
+BASHCOV>f4697250-c3da-4086-.....set -e
+BASHCOV>f4697250-c3da-4086-.....[[ '' == '' ]]
+BASHCOV>f4697250-c3da-4086-.....echo no args in subprogram
no args in subprogram
Run completed using bashcov 1.8.2 with Bash 5.0, Ruby 2.7.0, and SimpleCov 0.15.1.
Coverage report generated for /bin/bash ./main.sh to ~/bashcov/coverage. 4 / 9 LOC (44.44%) covered.

我们没有子程序的覆盖率信息:

所以。。。

如果从python调用,它放入环境中的文件描述符“8”在子程序中似乎不再有效,但当一个bash程序直接调用另一个时,它在某种程度上是有效的。我还尝试使用以下方式调用子流程 shell=True 结果是子程序没有错误和覆盖信息。

有人知道它是如何组合在一起的吗?为什么文件描述符在直接从main调用的bash程序中有效,而在从python调用的程序中无效?

我知道它在python调用的子程序中使用了bashcov,因为我破解了bashcvo,使用了stderr而不是自定义文件描述符。。。这适用于早于4.1的bash版本

      # Older versions of Bash (< 4.1) don't have the BASH_XTRACEFD variable
+      if Bashcov.bash_xtracefd? and false
-      if Bashcov.bash_xtracefd?
        options[fd] = fd # bind FDs to the child process

        env["BASH_XTRACEFD"] = fd.to_s
      else
        # Send subprocess standard error to @xtrace.file_descriptor
        options[:err] = fd

        # Don't bother issuing warning if we're silencing output anyway
        unless Bashcov.mute
          write_warning <<-WARNING
            you are using a version of Bash that does not support
            BASH_XTRACEFD. All xtrace output will print to standard error, and
            your script's output on standard error will not be printed to the
            console.
          WARNING
        end

得到了这个:

我几乎可以在不使用的情况下显示正在发生的事情 bashcov 完全。 这实际上只是一个关于python和linux的问题。也许我应该提出一个新问题:

我创建了一组新的示例程序,如下所示:

==> m.sh <==
#! /usr/bin/env bash

set -e

exec 3<>messages

ls -l /proc/$$/fd/

echo bash program called directly
./s.sh

==> r.py <==
import subprocess
import sys
import os

print("python program:")
subprocess.run(["ls", "-l", "/proc/%s/fd/" % os.getpid()])
print("bash program called by python:")
subprocess.run(sys.argv[1:], check=True)

==> s.sh <==
#! /usr/bin/env bash

set -e

ls -l /proc/$$/fd/

这就是结果

$ ./m.sh 
total 0
lrwx------ 1 me me 64 Apr 15 22:43 0 -> /dev/pts/2
l-wx------ 1 me me 64 Apr 15 22:43 1 -> pipe:[188295]
lrwx------ 1 me me 64 Apr 15 22:43 2 -> /dev/pts/2
lr-x------ 1 me me 64 Apr 15 22:43 255 -> /home/me/bashcov/m.sh
lrwx------ 1 me me 64 Apr 15 22:43 3 -> /home/me/bashcov/messages
bash program called directly
total 0
lrwx------ 1 me me 64 Apr 15 22:43 0 -> /dev/pts/2
l-wx------ 1 me me 64 Apr 15 22:43 1 -> pipe:[188295]
lrwx------ 1 me me 64 Apr 15 22:43 2 -> /dev/pts/2
lr-x------ 1 me me 64 Apr 15 22:43 255 -> /home/me/bashcov/s.sh
lrwx------ 1 me me 64 Apr 15 22:43 3 -> /home/me/bashcov/messages
python program:
total 0
lrwx------ 1 me me 64 Apr 15 22:43 0 -> /dev/pts/2
l-wx------ 1 me me 64 Apr 15 22:43 1 -> pipe:[188295]
lrwx------ 1 me me 64 Apr 15 22:43 2 -> /dev/pts/2
lrwx------ 1 me me 64 Apr 15 22:43 3 -> /home/me/bashcov/messages
bash program called by python:
total 0
lrwx------ 1 me me 64 Apr 15 22:43 0 -> /dev/pts/2
l-wx------ 1 me me 64 Apr 15 22:43 1 -> pipe:[188295]
lrwx------ 1 me me 64 Apr 15 22:43 2 -> /dev/pts/2
lr-x------ 1 me me 64 Apr 15 22:43 255 -> /home/me/bashcov/s.sh

bash将所有文件描述符传递给子进程,但python不会。有人知道是否有办法改变这一点吗?