'niceness of priting' test failure on Julia 1 - ubuntu-latest - x64

[glennmoy]

https://github.com/JuliaDiff/ChainRulesTestUtils.jl/runs/3318210603?check_suite_focus=true

niceness of printing: Test Failed at /home/runner/work/ChainRulesTestUtils.jl/ChainRulesTestUtils.jl/test/rand_tangent.jl:113
  Expression: length(string(rand_tangent(1.0f0))) <= 12
   Evaluated: 13 <= 12
Stacktrace:
 [1] macro expansion
   @ ~/work/ChainRulesTestUtils.jl/ChainRulesTestUtils.jl/test/rand_tangent.jl:113 [inlined]
 [2] macro expansion
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
 [3] macro expansion
   @ ~/work/ChainRulesTestUtils.jl/ChainRulesTestUtils.jl/test/rand_tangent.jl:109 [inlined]
 [4] macro expansion
   @ /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
 [5] top-level scope
   @ ~/work/ChainRulesTestUtils.jl/ChainRulesTestUtils.jl/test/rand_tangent.jl:8

[simeonschaub]

I have seen this spring up in PkgEval as well. What does this actually test?

[oxinabox]

There is special code that makes sure that rand_tangent only generates tangents that can be printed fairly compactly.
It does things like rounding in base 2 to a specific number of significant digits.
It seems like it doesn't always work, (which would be an issue with Base).
Or perhaps just the bounds on those tests are wrong.