Failed tests on Catalina buld

I'm experiencing a few test errors while building LO on Catalina/Xcode 11.

They're all equality assertions that fail. I have noted elsewhere that CLT
on Xcode11 apparently have some bugs, but I don't know if they're related
here.

Just for my amusement I commented out the offending tests to let it finish,
and it does appear to load up fine, at least without getting much beyond
creating a new document etc.

Anyone able to advise if it's my setup, or some new 'features' brought in
with Xcode11?

Relevant lines from the build log here:
/Users/builduser/libreoffice/core/chart2/qa/extras/chart2import.cxx:1533
: Assertion
Test name: Chart2ImportTest::testAxisTitlePositionDOCX
equality assertion failed
- Expected: 7157
- Actual  : 7159
/Users/builduser/libreoffice/core/sd/qa/unit/export-tests-ooxml2.cxx:1631
: Assertion
Test name: SdOOXMLExportTest2::testFontScale
equality assertion failed
- Expected: 73000
- Actual  : 55000
/Users/builduser/libreoffice/core/sw/qa/extras/ooxmlimport/ooxmlimport.cxx:
572: Assertion
Test name: testGroupshapeChildRotation::Import
equality assertion failed
- Expected: 686
- Actual  : 688
/Users/builduser/libreoffice/core/vcl/qa/cppunit/gen/gen.cxx:76: Assertion
Test name: testTdf121120::TestBody
equality assertion failed
- Expected: 255
- Actual  : 1
/Users/builduser/libreoffice/core/chart2/qa/extras/chart2export.cxx:1977
: Assertion
Test name: Chart2ExportTest::testAxisTitlePositionDOCX
assertion failed
- Expression: nY > 0.805152 && nY < 0.805153