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After upgrading mc to mc 4.6.1-3 I see these msg after runing mc or mcedit as root:
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified
I tried to downgrade to mc from current but pacman says:
error: archive mc-4.6.1-2.pkg.tar.gz is corrupted
( I cleared the cache and used wget to download it )
Edit:
I found out that mc from testing is compiled --with-x, what does it do/add?
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Try issuing
xhost +localhost
under the user you run X
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