树莓派更换清华源，安装aptitude报错：Unable to correct problems, you have held...

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[size=1em][size=1em]pi@raspberrypi:~ $ sudo apt-get install aptitude3 g/ S% v9 ?1 Y; Q, I1 E% f" n
[size=1em]Reading package lists... Done
. E+ r& W% `( C' `  U9 r& J9 g[size=1em]Building dependency tree      
0 F1 `! L2 c& F- U( t3 }, l[size=1em]Reading state information... Done  A1 G1 S5 d% W2 z( }; L6 q( d0 y
[size=1em]Some packages could not be installed. This may mean that you have, Q& v/ S& _$ |3 d4 v
[size=1em]requested an impossible situation or if you are using the unstable
" }! D; }7 W; n7 @4 D1 A0 n2 ][size=1em]distribution that some required packages have not yet been created# E& I! I& Q- I
[size=1em]or been moved out of Incoming.! g# I$ K/ O; g, ~
[size=1em]The following information may help to resolve the situation:
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[size=1em]The following packages have unmet dependencies:
: B8 X/ q; y  a( ^[size=1em] aptitude : Depends: libapt-pkg5.0 (>= 1.1) but it is not going to be installed0 \* |5 x3 Y% U
[size=1em]            Recommends: libparse-debianchangelog-perl but it is not going to be installed
- G. A- r8 _+ j6 H  e+ ~[size=1em]E: Unable to correct problems, you have held broken packages.
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