check50._api.run returns stdout+stderr

[pazz]

Hi!
I've recently noticed some unexpected behaviour when running check50_.api.run on some command that outputs both to stdout (which I want as string) and stderr (which I want to ignore). I get both.

I am running this command:

 java -jar /home/pazz/.local/lib/python3.9/site-packages/check50_checkstyle/lib/checkstyle-8.39-all.jar -c naming-conventions.xml -f xml *.java

where the output on stdout is some XML report that I parse:

<?xml version="1.0" encoding="UTF-8"?>
<checkstyle version="8.39">
<file name="/home/pazz/repo/teaching/2021-COMP122/content/lectures/code/l9a/EmptyGUI.java">
</file>
<file name="/home/pazz/repo/teaching/2021-COMP122/content/lectures/code/l9a/Gui.java">
<error line="3" column="42" severity="error" message="Array brackets at illegal position." source="com.puppycrawl.tools.checkstyle.checks.ArrayTypeStyleCheck"/>
</file>
<file name="/home/pazz/repo/teaching/2021-COMP122/content/lectures/code/l9a/LabelFrame.java">
</file>
<file name="/home/pazz/repo/teaching/2021-COMP122/content/lectures/code/l9a/NoLayout.java">
</file>
</checkstyle>

plus a summary (which I cannot suppress)

Checkstyle ends with 1 errors.

When I run this using the check50 API i get the concatenation as sole string result:

<?xml version="1.0" encoding="UTF-8"?>\n<checkstyle version="8.39">\n<file name="/tmp/tmpd2chxmcv/checkstyle_naming_conventings/EmptyGUI.java">\n</file>\n<file name="/tmp/tmpd2chxmcv/checkstyle_naming_conventings/Gui.java">\n<error line="3" column="42" severity="error" message="Array brackets at illegal position." source="com.puppycrawl.tools.checkstyle.checks.ArrayTypeStyleCheck"/>\n</file>\n<file name="/tmp/tmpd2chxmcv/checkstyle_naming_conventings/LabelFrame.java">\n</file>\n<file name="/tmp/tmpd2chxmcv/checkstyle_naming_conventings/NoLayout.java">\n</file>\n</checkstyle>\nCheckstyle ends with 1 errors.\n

A hotfix for me is to append " 2>/dev/null" to the command, but this is obviously ugly and may only work as long as check50 uses a shell to interpret these commands.

Question/feature request: can we have a parameter to _api.run that allows to supress stdout?