Depends: libgflags2v5 but it is not installable

[christroutner]

Running through the User Manual I'm trying to install the Blockbook API for Bitcoin Cash. I was able to successfully run make all-bcash and build the deb file on a new installation of Ubuntu 18.04. However, when I try to install the generated .deb file (blockbook-bcash_0.2.2_amd64.deb), I get this error:

The following packages have unmet dependencies:
 blockbook-bcash : Depends: libgflags2v5 but it is not installable
E: Unable to correct problems, you have held broken packages.

Did some research and found this page, which seems to indicate that the libgflags2v5 library in Ubuntu 16.04, was renamed to libgflags2.2 in Ubuntu 18.04.

I believe the renaming of the library is the reason for the error.

[martinboehm]

Hi. Our build process supports only Debian 9. However, there are people, who managed to run Blockbook on Ubuntu successfully, see for example this issue.

[christroutner]

Thanks for the link to that Issue. I was able to follow those suggestions and change this line to Ubuntu:

blockbook/build/docker/bin/Dockerfile

Line 3 in 3e67307

FROM debian:9

The install of the compiled .deb file after that completing successfully.

[christroutner]

For those who follow after me, I've forked this repository to target Ubuntu 18.04:
https://github.com/christroutner/blockbook

I've also created a Docker container running Blockbook that targets Bitcoin Cash:
https://github.com/christroutner/docker-ubuntu-blockbook

Details on my experience running Blockbook with Bitcoin Cash can be found on my blog:
http://troutsblog.com/research/bitcoin-cash/blockbook

[martinboehm]

Hi, I will give an explanation of the workers issue that you describe in your blog:

• it is either -workers=1, in which case Blockbook not only uses only one thread to fetch data from the backend, it also turns off the bulk import mode (which caches a lot of data in memory and also puts the database in inconsistent mode). So with -workers=1 even if Blockbook is killed unexpectedly, there is a good chance that the DB will not be corrupted (we use RocksDB transactions to store data).

• or you set workers to any value greater than one and it turns on the bulk import mode (with caching and inconsistent DB)