When reporting InvalidInterface exceptions, say which feed had the error
tree68b75f5de0b12b73c03a59c0755e3d8309920989
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-rw-r--r-- 26536 COPYING
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-rw-r--r-- 2115 README
-rw-r--r-- 2183 ZeroInstall.xml
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-rw-r--r-- 5403 setup.py
drwxr-xr-x - share
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drwxr-xr-x - zeroinstall