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 aptitude2 L7 L( J& _% L6 q
[size=1em]Reading package lists... Done, r) x& R/ w6 K7 t
[size=1em]Building dependency tree      
) R% M7 H1 s/ j[size=1em]Reading state information... Done
8 M% ^- K: A8 d9 `[size=1em]Some packages could not be installed. This may mean that you have! Z- T/ [/ {7 v; F
[size=1em]requested an impossible situation or if you are using the unstable
! E2 e  r0 u2 m: I* \[size=1em]distribution that some required packages have not yet been created/ _5 g5 L, H  q9 X2 }+ j2 q
[size=1em]or been moved out of Incoming.: A% q  b1 I5 X: p) i7 f
[size=1em]The following information may help to resolve the situation:
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% R/ T/ z/ D0 \7 F- B[size=1em]The following packages have unmet dependencies:
  I+ E3 s$ K3 J! J! e[size=1em] aptitude : Depends: libapt-pkg5.0 (>= 1.1) but it is not going to be installed* I% C  B; h  A+ X4 X/ F, ]9 v
[size=1em]            Recommends: libparse-debianchangelog-perl but it is not going to be installed
+ H% I* `  h; `( C! [[size=1em]E: Unable to correct problems, you have held broken packages.
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