Consider using qt 4.8.6 for linux builds #4495

We discovered an issue: "undefined symbol: _ZN10QTextCodec11validCodecsEv" also documented on bitcointalk, https://bitcointalk.org/index.php?topic=655359.msg7498801#msg7498801 which meant bitcoin-qt could not be executed on CentOS (6.5).

We swapped to qt 4.8.6 when gitian building the release for linux, and it has fixed the issue, and has also improved the general rendering of the qt client.

Tested the result on various debian/ubuntu systems, and also centos 6.5, everything works as expected.

https://download.qt-project.org/archive/qt/4.8/4.8.6/ for source.

No code was updated other than references in the gitian descriptors for linux.

We're actually going to update to Qt 5.2.1, see #4284

But thanks for reporting this.

It is actually very strange. For 0.9.2 we switched to an older version of Qt (4.6.3) to be able to be compatible with as many Linux distributions as possible. But seemingly it broke compatibility with CentOS 6, which does have a more recent Qt 4.x?

Anyhow - static linking will solve this.

Agreed, and thank you for getting back to me.

Can I ask two questions while I am here:

1. any idea when the next tagged version of bitcoin is due to be released?
2. would you class this forked code as acceptable, https://github.com/project-bitmark/bitmark/blob/master/src/bitmarkd.cpp particularly the file header.

Thank you for your extensive efforts on the bitcoin codebase, they are appreciated.

1. No date has been set. The next version will likely be 0.10.0, and as there are lots of changes that first need to peter out, it may take a while. But it will be less than a year this time :) There may be another 0.9.x release if there happens to be a critical issue.
2. Yes, that's fine.

We may be in an position to merge in specific changes, so as to trial run them live before they go in to bitcoin, if that would help?

Our project is young, but based on 0.9.2.1, perhaps we can come back to this in a few weeks or months if the service would be of use.