Failed to fetch - Installation errors

Question

I am trying to make updates and installations and I keep getting errors like:

Err:1 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 cpp-8 amd64 8.3.0-6ubuntu1~18.04.1

What do I need to do to rectify these errors?

Here is the full attempt:

sudo apt install gcc-8
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  cpp-8 gcc-10-base gcc-9-base libasan5 libgcc-8-dev libgcc-s1 libubsan1
Suggested packages:
  gcc-8-locales gcc-8-multilib gcc-8-doc libgcc1-dbg libgomp1-dbg libitm1-dbg libatomic1-dbg libasan5-dbg liblsan0-dbg libtsan0-dbg libubsan1-dbg
  libmpx2-dbg libquadmath0-dbg
The following NEW packages will be installed:
  cpp-8 gcc-10-base gcc-8 gcc-9-base libasan5 libgcc-8-dev libgcc-s1 libubsan1
0 upgraded, 8 newly installed, 0 to remove and 13 not upgraded.
Need to get 21.0 MB/21.6 MB of archives.
After this operation, 72.2 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Err:1 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 cpp-8 amd64 8.3.0-6ubuntu1~18.04.1
  404  Not Found [IP: 91.189.88.142 80]
Err:2 http://security.ubuntu.com/ubuntu bionic-security/main amd64 libgcc-8-dev amd64 8.3.0-6ubuntu1~18.04.1
  404  Not Found [IP: 91.189.88.142 80]
Err:3 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 gcc-8 amd64 8.3.0-6ubuntu1~18.04.1
  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/g/gcc-8/cpp-8_8.3.0-6ubuntu1~18.04.1_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/gcc-8/libgcc-8-dev_8.3.0-6ubuntu1~18.04.1_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/universe/g/gcc-8/gcc-8_8.3.0-6ubuntu1~18.04.1_amd64.deb  404  Not Found [IP: 91.189.88.142 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing
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Also the scroll wheel does not work, but I don't know if it associated with this problem.

Thank you

Answer 1

As APT say 404 not found it means that repository information is outdated. You can easily solve it by issuing this command on terminal:

sudo apt update

Now retry to install your package and the installation process would be smooth.

Answer 2

You need to update the repository data by executing sudo apt update before your installation. That is:

1. sudo apt update.
2. sudo apt install gcc-8.

Alternatively, you could just run:

sudo apt update && sudo apt install gcc-8

---

Note: It's a good practice to always execute updates before any installation.