document is missing instruction from Configuring and Building Qt for QNX -section
When running configure
"Project ERROR: QNX_TARGET environment variable not set"
So something like this should be added to Configuring and Building Qt for QNX -section
To set env variables qnxsdp-env script has to be run before running configure.
qnxsdp-env.sh that is included in QNX Software Development Platform (SDP).
By default, the path is /opt/qnx700 in Linux and C:\qnx700 in Windows.
Linux: source /opt/qnx700/.qnxsdp-env.sh
Script is mentioned in Building Qt Safe Renderer and Examples -section.