This question is a bit old now but the solution(s) are still valid. I have found that the most difficult part of getting gitian builder working is the setup of LXC. Apparently it is still valid to use the KVM method but I have never done this and from what I understand, KVM is the old method. Be sure to carefully read over the entire build instructions at https://github.com/bitcoin-core/docs/blob/master/gitian-building.md and any pages it links to for a full understanding of how this all can be done.
Assuming that you have LXC setup correctly, there are also a couple problems with your build cmd. Here is what you were using:
sudo ./gitian-build.sh --build achow101
and if using the gitian-build.sh script, you should be using this syntax instead:
./gitian-build.sh --detach-sign --no-commit -b achow101 0.17.1
- Root access is not required or desired for the build procedure so remove the
achow101 is the github username you wish to create sigs for. if you aren't planning to upload or do anything with your sigs then it doesn't matter what you enter here as long as it has a value.
0.17.1 is the version tag that you would like to build. You can use gitian-builder to build wallets for older versions of bitcoin so you need to specify which version you want.
0.17.1 happens to be the most current bitcoin wallet tag version as of this writing. You can find the tag versions here: https://github.com/bitcoin/bitcoin/tags. You must always be sure to omit the
v prefix since for some silly reason the script wants to automatically add the prefix itself, so if you tried to run
./gitian-build.sh --detach-sign --no-commit -b achow101 v0.17.1 it would error out on trying to download the tag
The other big thing to note here is that the
gitian-build.sh bash script was replaced by a python script
gitian-build.py right around the same time that you posted this question. Therefore, if you are using one of the newer builds of bitcoin core with the new python script you will have to change the build cmd ever so slightly:
./gitian-build.py --detach-sign --no-commit -b achow101 0.17.1
Final note: I don't have a proper list of error msgs, but in my experience there are 2-3 errors that you can intermittently get during gitian building that will stop the build process even when everything is correct. This can be very frustrating when you are trying to learn to build wallets and I have not yet found the reason for this. The workaround is easy, just run the exact same cmd again and 99% of the time it works fine the 2nd time even though it gave an error before.