Build fails on armv7: non-constant-expression cannot be narrowed from type 'double' to 'float' in initializer list

[yurivict]

/wrkdirs/usr/ports/audio/qtractor/work/qtractor-qtractor_0_9_27/src/qtractorAudioMonitor.cpp:167:3: error: non-constant-expression cannot be narrowed from type 'double' to 'float' in initializer list [-Wc++11-narrowing]
                fGainIter + 2.0 * fGainStepSingle,
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/wrkdirs/usr/ports/audio/qtractor/work/qtractor-qtractor_0_9_27/src/qtractorAudioMonitor.cpp:167:3: note: insert an explicit cast to silence this issue
                fGainIter + 2.0 * fGainStepSingle,
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                static_cast<float>(              )
/wrkdirs/usr/ports/audio/qtractor/work/qtractor-qtractor_0_9_27/src/qtractorAudioMonitor.cpp:168:3: error: non-constant-expression cannot be narrowed from type 'double' to 'float' in initializer list [-Wc++11-narrowing]
                fGainIter + 3.0 * fGainStepSingle };
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/wrkdirs/usr/ports/audio/qtractor/work/qtractor-qtractor_0_9_27/src/qtractorAudioMonitor.cpp:168:3: note: insert an explicit cast to silence this issue
                fGainIter + 3.0 * fGainStepSingle };
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                static_cast<float>(              )
2 errors generated.

The failure is spotted on armv7 but this is likely a general problem that should be fixed.

Version: 0.9.27
clang-11
FreeBSD 13.0-RELEASE

[rncbc]

the case is only on (old) armv7/neon builds, maybe fixed in da1609cfb