I have run into an odd situation, where Anaconda repo page clearly states that the newest version of Blast in Bioconda channel is 2.7.1, however the version Conda wants to install (command conda install -c bioconda blast) is 2.6.0.

Even specifying the version with command conda install -c bioconda blast=2.7.1 does not work and Conda returns a PackagesNotFoundError.

By observing the webpage mentioned above, one can see that there is a "v" before the version number, however adding this letter to the command with specified version did not help.

To make things even more odd, conda search blast returns a list of Blast versions available and there is a 2.7.1 version available in Bioconda channel.

I have added the Bioconda channel into my Conda.

My question is: How can I install the 2.7.1 (by the time of writing this question the newest version available in Anaconda repo) through Conda?

Edit: I have Ubuntu Server 18.04 LTS and Conda 4.5.11.


1 Answer 1


I was able to reproduce your problem, even in a blank environment.

$ conda create -n test
$ conda activate test
$ conda install bioconda::blast=2.7.1
Solving environment: failed

PackagesNotFoundError: The following packages are not available from current channels:

  - bioconda::blast=2.7.1
  - boost=1.64
  - bioconda::blast=2.7.1
  - gnutls
  - bioconda::blast=2.7.1
  - nettle[version='3.3|3.3.*']
  - bioconda::blast=2.7.1

Note that boost, gnutls, and nettle are listed as requirements here.

If you do a search for those packages, you'll see that boost is available in a default channel, whereas gnutls and nettle are only in the conda-forge channel, which is not a default. Adding those packages to the install command resolved this issue, for me.

$ conda install bioconda::blast=2.7.1 conda-forge::gnutls conda-forge::nettle --dry-run
Solving environment: done

## Package Plan ##

environment location: /Users/hawleyj/anaconda3/envs/test

added / updated specs: 
    - bioconda::blast=2.7.1
    - conda-forge::gnutls
    - conda-forge::nettle

As mentioned in the comment below, to avoid this issue entirely, before using Bioconda packages make sure you run the proper channel configuration first.

conda config --add channels defaults
conda config --add channels bioconda
conda config --add channels conda-forge

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