Dear Xiangjun, The Nektar apt key is available at http://www.nektar.info/nektar-apt.gpg Some details are provided on the downloads page (https://www.nektar.info/downloads/) in the "Package repositories" section but to summarise, you should be able to download the key file, then run "apt-key add nektar-apt.gpg" (I think this may require sudo). Once you have done this, "sudo apt-get update" should work and you'll be able to install the Nektar++ packages on Ubuntu Bionic using "sudo apt-get install nektar++" Kind regards, Jeremy On 20 Jun 2020, at 13:52, shan xiangjun <x_j_shan@outlook.com> wrote:

Dear Nektar:

I want to install Nektar++ on Win10-WSL: Ubuntu 18.04 using the pre-compiled packages, but I encountered a problem.

After Code: sudo apt-get update

I get the following:

Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB] Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease Get:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB] Get:1 https://www.nektar.info/ubuntu-bionic bionic InRelease [6114 B] Get:5 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB] Err:1 https://www.nektar.info/ubuntu-bionic bionic InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY DB5E71FF7AC99B37 Reading package lists... Done W: GPG error: https://www.nektar.info/ubuntu-bionic bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY DB5E71FF7AC99B37 E: The repository 'http://www.nektar.info/ubuntu-bionic bionic InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.

I have tried the following: Using different servers such as the following:

code: curl -sL http://keyserver.ubuntu.com/pks/lookup?op=get&search=0xDB5E71FF7AC99B37 | sudo apt-key add gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv DB5E71FF7AC99B37 curl -sL "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0xDB5E71FF7AC99B37" | sudo apt-key add sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys DB5E71FF7AC99B37 sudo apt-key adv --hkp://keys.gnupg.net--recv-keys DB5E71FF7AC99B37 gpg --keyserver hkp://pgpkeys.mit.edu --recv DB5E71FF7AC99B37

But, no good results.The key could not be found.Examples are listed below:

Executing: /tmp/apt-key-gpghome.IoDko6URV5/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys DB5E71FF7AC99B37 gpg: keyserver receive failed: No data

gpg: no valid OpenPGP data found.

Have tried to see if key exists with command: code:

apt-key list

but it is not listed there.

/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-archive.gpg ------------------------------------------------------ pub rsa4096 2012-05-11 [SC] 790B C727 7767 219C 42C8 6F93 3B4F E6AC C0B2 1F32 uid [ unknown] Ubuntu Archive Automatic Signing Key (2012) <ftpmaster@ubuntu.com>

/etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg ------------------------------------------------------ pub rsa4096 2012-05-11 [SC] 8439 38DF 228D 22F7 B374 2BC0 D94A A3F0 EFE2 1092 uid [ unknown] Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>

/etc/apt/trusted.gpg.d/ubuntu-keyring-2018-archive.gpg ------------------------------------------------------ pub rsa4096 2018-09-17 [SC] F6EC B376 2474 EDA9 D21B 7022 8719 20D1 991B C93C uid [ unknown] Ubuntu Archive Automatic Signing Key (2018) <ftpmaster@ubuntu.com>

Regards, Xiangjun x_j_shan@outlook.com

As you can see, many avenues explored with no good results. Looking for some help, please _______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users