build broken on last ubuntu 20.04

[valdirSalgueiro]

linuxdeployqt 6 (commit c6bcad2), build 715 built on 2020-04-12 12:21:56 UTC
ERROR: The host system is too new.
Please run on a system with a glibc version no newer than what comes with the oldest
currently still-supported mainstream distribution (xenial), which is glibc 2.23.
This is so that the resulting bundle will work on most still-supported Linux distributions.
For more information, please see
probonopd/linuxdeployqt#340

[christopherpow]

This is not a build problem it is a deployment requirement. If you intend to deploy you must use a build machine with Ubuntu 16.04. For build purposes you should be able to use the binaries built from qmake && make.

[ArbitCode]

@christopherpow thank you to reply,
I have installed Ubuntu 16.04 on virtual box and shared binaries built from qmake there, but while generating there is show error that error is as following

QDir does not exist type

[christopherpow]

QDir does not exist type

I am unable to reproduce this.