Bug#943549: dymo-cups-drivers FTBFS: ../common/CupsPrintEnvironment.cpp:139:23: error: ‘cupsBackChannelRead’ was not declared in this scope

[Helmut Grohne <helmut@subdivi.de>]

Source: dymo-cups-drivers
Version: 1.4.0-8
Severity: serious
Tags: ftbfs

dymo-cups-drivers fails to build from source in unstable using sbuild on
amd64. The compiler error is quite hidden in the amount of warnings:

| ../common/CupsPrintEnvironment.cpp: In member function 'virtual void DymoPrinterDriver::CCupsPrintEnvironmentForLM::ReadData(DymoPrinterDriver::buffer_t&)':
| ../common/CupsPrintEnvironment.cpp:139:23: error: 'cupsBackChannelRead' was not declared in this scope
|   139 |   ssize_t bytesRead = cupsBackChannelRead((char*)buf, sizeof(buf), 2.5);
|       |                       ^~~~~~~~~~~~~~~~~~~

This is also reproduced on reproducible builds and crossqa:
https://tests.reproducible-builds.org/debian/rbuild/unstable/amd64/dymo-cups-drivers_1.4.0-8.rbuild.log.gz
http://crossqa.debian.net/build/dymo-cups-drivers_1.4.0-8_arm64_20190930205510.log

Helmut