<p dir="auto">This issue is carried over from <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="22984422" data-permission-text="Title is private" data-url="https://github.com/JuliaLang/IJulia.jl/issues/116" data-hovercard-type="issue" data-hovercard-url="/JuliaLang/IJulia.jl/issues/116/hovercard" href="https://github.com/JuliaLang/IJulia.jl/issues/116">JuliaLang/IJulia.jl#116</a>.</p>
<p dir="auto">It would be useful at times to have a means of suppressing warnings such as the example below without suppressing errors.</p>
<p dir="auto"><a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/staticfloat/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/staticfloat">@staticfloat</a> has expressed interest in this issue, as has <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/StefanKarpinski/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/StefanKarpinski">@StefanKarpinski</a>. /base/util.jl lines 418:446 contains what looks like the seed of a lightweight logging approach along the lines <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="/users/StefanKarpinski/hovercard" data-octo-click="hovercard-link-click" data-octo-dimensions="link_type:self" href="https://github.com/StefanKarpinski">@StefanKarpinski</a> mentioned in the IJulia discussion</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; using Winston
Warning: New definition
    |(SynchronousStepCollection,Any) at C:\Users\keithc\.julia\BinDeps\src\BinDe
ps.jl:283
is ambiguous with:
    |(Any,NAtype) at C:\Users\keithc\.julia\DataArrays\src\operators.jl:502.
To fix, define
    |(SynchronousStepCollection,NAtype)
before the new definition.
Warning: New definition
    |(Any,SynchronousStepCollection) at C:\Users\keithc\.julia\BinDeps\src\BinDe
ps.jl:286
is ambiguous with:
    |(NAtype,Any) at C:\Users\keithc\.julia\DataArrays\src\operators.jl:502.
To fix, define
    |(NAtype,SynchronousStepCollection)
before the new definition."><pre class="notranslate"><code class="notranslate">julia&gt; using Winston
Warning: New definition
    |(SynchronousStepCollection,Any) at C:\Users\keithc\.julia\BinDeps\src\BinDe
ps.jl:283
is ambiguous with:
    |(Any,NAtype) at C:\Users\keithc\.julia\DataArrays\src\operators.jl:502.
To fix, define
    |(SynchronousStepCollection,NAtype)
before the new definition.
Warning: New definition
    |(Any,SynchronousStepCollection) at C:\Users\keithc\.julia\BinDeps\src\BinDe
ps.jl:286
is ambiguous with:
    |(NAtype,Any) at C:\Users\keithc\.julia\DataArrays\src\operators.jl:502.
To fix, define
    |(NAtype,SynchronousStepCollection)
before the new definition.
</code></pre></div>
<p dir="auto">I got the above error locally with  <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="906350454" data-permission-text="Title is private" data-url="https://github.com/JuliaLang/julia/issues/40996" data-hovercard-type="pull_request" data-hovercard-url="/JuliaLang/julia/pull/40996/hovercard" href="https://github.com/JuliaLang/julia/pull/40996">#40996</a>, which I have never seen before.</p>
<p dir="auto">CI sees it too, here:  <a href="https://build.julialang.org/#/builders/7/builds/5932/steps/5/logs/stdio" rel="nofollow">https://build.julialang.org/#/builders/7/builds/5932/steps/5/logs/stdio</a> (<a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/JuliaLang/julia/commit/17f851b11e09303df3c485740745abb91db1a71c/hovercard" href="https://github.com/JuliaLang/julia/commit/17f851b11e09303df3c485740745abb91db1a71c"><tt>17f851b</tt></a>)</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="arrayops                           (5) |         failed at 2021-11-13T02:50:50.671
Error During Test at /buildworker/worker/tester_linuxaarch64/build/share/julia/test/arrayops.jl:1149
  Got exception outside of a @test
  fatal error in type inference (type bound)
  Stacktrace:
    [1] mapslices(f::Main.Test99Main_arrayops.var&quot;#18#31&quot;, A::Matrix{Int64}; dims::Int64)
      @ Base ./abstractarray.jl:2803
    [2] macro expansion
      @ /buildworker/worker/tester_linuxaarch64/build/share/julia/test/arrayops.jl:1196 [inlined]"><pre class="notranslate"><code class="notranslate">arrayops                           (5) |         failed at 2021-11-13T02:50:50.671
Error During Test at /buildworker/worker/tester_linuxaarch64/build/share/julia/test/arrayops.jl:1149
  Got exception outside of a @test
  fatal error in type inference (type bound)
  Stacktrace:
    [1] mapslices(f::Main.Test99Main_arrayops.var"#18#31", A::Matrix{Int64}; dims::Int64)
      @ Base ./abstractarray.jl:2803
    [2] macro expansion
      @ /buildworker/worker/tester_linuxaarch64/build/share/julia/test/arrayops.jl:1196 [inlined]
</code></pre></div>