Dependency error when installing gcc-multilib

Question

I currently try to install gcc-multilib on my Ubuntu 16.04.4 LTS machine (freshly done apt-get update + upgrade).

There are several dependencies and that's why I tried it with aptitude to resolve them automatically. Here is my current output:

me@my_machine:~$ sudo aptitude install gcc-multilib
The following NEW packages will be installed:
  gcc-5-multilib{a} gcc-multilib{b} lib32asan2{a} lib32atomic1{a} lib32cilkrts5{a} lib32gcc-5-dev{a} lib32gomp1{a} lib32itm1{a} lib32mpx0{a} lib32quadmath0{a} lib32ubsan0{a} libc6-dev-i386{a} 
  libc6-dev-x32{a} libc6-x32{a} libx32asan2{a} libx32atomic1{a} libx32cilkrts5{a} libx32gcc-5-dev{a} libx32gcc1{ab} libx32gomp1{a} libx32itm1{a} libx32quadmath0{a} libx32stdc++6{a} libx32ubsan0{a} 
0 packages upgraded, 24 newly installed, 0 to remove and 0 not upgraded.
Need to get 11,1 MB of archives. After unpacking 46,2 MB will be used.
The following packages have unmet dependencies:
 libx32gcc1 : Depends: gcc-6-base (= 6.0.1-0ubuntu1) but 6.3.0-18ubuntu2~16.04 is installed.
 gcc-5-aarch64-linux-gnu : Conflicts: gcc-multilib but 4:5.3.1-1ubuntu1 is to be installed.
 gcc-multilib : Conflicts: gcc-5-aarch64-linux-gnu but 5.4.0-6ubuntu1~16.04.9cross1 is installed.
                Conflicts: gcc-5-aarch64-linux-gnu:i386 but it is not going to be installed.
The following actions will resolve these dependencies:

      Keep the following packages at their current version:
1)      gcc-5-multilib [Not Installed]                     
2)      gcc-multilib [Not Installed]                       
3)      lib32gcc-5-dev [Not Installed]                     
4)      libx32asan2 [Not Installed]                        
5)      libx32cilkrts5 [Not Installed]                     
6)      libx32gcc-5-dev [Not Installed]                    
7)      libx32gcc1 [Not Installed]                         
8)      libx32stdc++6 [Not Installed]                      
9)      libx32ubsan0 [Not Installed]                       

      Leave the following dependencies unresolved:         
10)     libc6-dev-i386 recommends gcc-multilib             


Accept this solution? [Y/n/q/?] Y
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.

It seems like the current gcc-multilib needs an older version of gcc-6-base than the current one, but both of them are the newest ones aptitude can find.

My current gcc version is the following (gcc --version): gcc (Ubuntu 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609. But I have installed the newest gcc-6-base.

What are my options? Is downgrading gcc-6-base the only option to get the install done?

Is it possible that two upstream packages from gcc are not compatible or is it a problem with my machine?

Some more details about my machine:

uname -a
Linux huhuhu-UBUNTU 4.4.0-128-generic #154-Ubuntu SMP Fri May 25 14:15:18 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

---

Answer for the comment (but after I did my solution):

apt-cache policy gcc-6-base
gcc-6-base:
  Installed: 6.0.1-0ubuntu1
  Candidate: 6.0.1-0ubuntu1
  Version table:
 *** 6.0.1-0ubuntu1 500
        500 http://de.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status

Solution

I managed to install gcc-multilib but with a downgrade for some components. Don't know if it is a good solution but it worked.

My solution was to install gcc-5-multilib and press n when aptitude asked for the first time "Accept this solution?" and Y on the second time. Output:

sudo aptitude install gcc-5-multilib
...
The following actions will resolve these dependencies:

      Keep the following packages at their current version:
1)      gcc-5-multilib [Not Installed]                     
2)      gcc-multilib [Not Installed]                       
3)      lib32gcc-5-dev [Not Installed]                     
4)      libx32asan2 [Not Installed]                        
5)      libx32cilkrts5 [Not Installed]                     
6)      libx32gcc-5-dev [Not Installed]                    
7)      libx32gcc1 [Not Installed]                         
8)      libx32stdc++6 [Not Installed]                      
9)      libx32ubsan0 [Not Installed]                       

      Leave the following dependencies unresolved:         
10)     libc6-dev-i386 recommends gcc-multilib             


Accept this solution? [Y/n/q/?] n
The following actions will resolve these dependencies:

     Remove the following packages:                                       
1)     gcc-6-base:i386                                                    

     Keep the following packages at their current version:                
2)     gcc-multilib [Not Installed]                                       

     Downgrade the following packages:                                    
3)     gcc-6-base [6.3.0-18ubuntu2~16.04 (now) -> 6.0.1-0ubuntu1 (xenial)]

     Leave the following dependencies unresolved:                         
4)     libc6-dev-i386 recommends gcc-multilib                             


Accept this solution? [Y/n/q/?] Y
The following packages will be DOWNGRADED:
  gcc-6-base 
The following NEW packages will be installed:
  gcc-5-multilib lib32asan2{a} lib32atomic1{a} lib32cilkrts5{a} lib32gcc-5-dev{a} lib32gomp1{a} lib32itm1{a} lib32mpx0{a} lib32quadmath0{a} lib32ubsan0{a} libc6-dev-i386{a} libc6-dev-x32{a} 
  libc6-x32{a} libx32asan2{a} libx32atomic1{a} libx32cilkrts5{a} libx32gcc-5-dev{a} libx32gcc1{a} libx32gomp1{a} libx32itm1{a} libx32quadmath0{a} libx32stdc++6{a} libx32ubsan0{a} 
The following packages will be REMOVED:
  gcc-6-base:i386{a} 
The following packages are RECOMMENDED but will NOT be installed:
  gcc-multilib 
0 packages upgraded, 23 newly installed, 1 downgraded, 1 to remove and 0 not upgraded.
Need to get 11,1 MB of archives. After unpacking 46,1 MB will be used.
Do you want to continue? [Y/n/?] Y
...

And afterwards I was able to install gcc-multilib:

sudo aptitude install gcc-multilib
The following NEW packages will be installed:
  gcc-multilib{b} 
0 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 1.212 B of archives. After unpacking 8.192 B will be used.
The following packages have unmet dependencies:
 gcc-5-aarch64-linux-gnu : Conflicts: gcc-multilib but 4:5.3.1-1ubuntu1 is to be installed.
 gcc-multilib : Conflicts: gcc-5-aarch64-linux-gnu but 5.4.0-6ubuntu1~16.04.9cross1 is installed.
                Conflicts: gcc-5-aarch64-linux-gnu:i386 but it is not going to be installed.
The following actions will resolve these dependencies:

     Remove the following packages:
1)     gcc-5-aarch64-linux-gnu     
2)     gcc-aarch64-linux-gnu       



Accept this solution? [Y/n/q/?] Y
The following NEW packages will be installed:
  gcc-multilib 
The following packages will be REMOVED:
  binutils-aarch64-linux-gnu{u} cpp-5-aarch64-linux-gnu{u} cpp-aarch64-linux-gnu{u} gcc-5-aarch64-linux-gnu{a} gcc-5-aarch64-linux-gnu-base{u} gcc-5-cross-base{u} gcc-aarch64-linux-gnu{a} 
  libasan2-arm64-cross{u} libatomic1-arm64-cross{u} libc6-arm64-cross{u} libc6-dev-arm64-cross{u} libgcc-5-dev-arm64-cross{u} libgcc1-arm64-cross{u} libgomp1-arm64-cross{u} libitm1-arm64-cross{u} 
  libstdc++6-arm64-cross{u} libubsan0-arm64-cross{u} linux-libc-dev-arm64-cross{u} 
0 packages upgraded, 1 newly installed, 18 to remove and 0 not upgraded.
Need to get 1.212 B of archives. After unpacking 60,8 MB will be freed.
Do you want to continue? [Y/n/?] Y

Comments

[user535733]

Looks like a classic version conflict. You previously installed a newer version of libx32gcc1 from some non-Ubuntu source. The software from that non-Ubuntu source is incompatible with the software you now want to install. Remove all software from that non-Ubuntu source, and disable the source.

[steeldriver]

Can you add the output of apt-cache policy gcc-6-base please? I'm curious where 6.3.0-18ubuntu2~16.04 comes from - I only see 6.0.1-0ubuntu1 in xenial

[izlin]

@steeldriver I added the information. I also posted an answer, maybe that had also an influence on this package.

[steeldriver]

Interesting - my system is not directly comparable because I have enabled the toolchain-r PPA, however if I try to apt-get install --dry-run gcc-5-aarch64-linux-gnu it also wants to remove g++-multilib gcc-multilib (and aptitude why-not gcc-5-aarch64-linux-gnu says gcc-multilib Conflicts gcc-5-aarch64-linux-gnu) so it seems like gcc-5-aarch64-linux-gnu is indeed the problem package.