<p dir="auto">I'm getting a test failure on <code class="notranslate">make test-backtrace</code>. More detail:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; bt = backtrace()
22-element Array{Ptr{Void},1}:
 Ptr{Void} @0x00007f695d467c85
 Ptr{Void} @0x00007f695d467ce0
 Ptr{Void} @0x00007f694d567010
 Ptr{Void} @0x00007f694d567030
 Ptr{Void} @0x00007f695d41aa66
 Ptr{Void} @0x00007f695d461598
 Ptr{Void} @0x00007f695d460b0f
 Ptr{Void} @0x00007f695d460901
 Ptr{Void} @0x00007f695d461b9a
 Ptr{Void} @0x00007f695d4600e8
 Ptr{Void} @0x00007f695d472567
 Ptr{Void} @0x00007f695d4228a6
 Ptr{Void} @0x00007f695ec314c6
 Ptr{Void} @0x00007f695ec315f7
 Ptr{Void} @0x00007f695d41a9da
 Ptr{Void} @0x00007f695ec980cf
 Ptr{Void} @0x00007f695d467b27
 Ptr{Void} @0x00007f695d466abf
 Ptr{Void} @0x00000000004014bd
 Ptr{Void} @0x00007f695cd05ec5
 Ptr{Void} @0x00000000004014f3
 Ptr{Void} @0x0000000000000000

julia&gt; for l in bt
           lkup = ccall(:jl_lookup_code_address, Any, (Ptr{Void},), l)
           @show lkup
       end
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513194117,true,140090513194117)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513194208,true,140090513194208)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090245804048,true,140090245804048)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090245804080,true,140090245804080)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090512878182,true,140090512878182)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513167768,true,140090513167768)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513165071,true,140090513165071)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513164545,true,140090513164545)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513169306,true,140090513169306)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513162472,true,140090513162472)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513237351,true,140090513237351)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090512910502,true,140090512910502)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090538136774,true,140090538136774)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090538137079,true,140090538137079)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090512878042,true,140090512878042)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090538557647,true,140090538557647)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513193767,true,140090513193767)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090513189567,true,140090513189567)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),4199613,true,4199613)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),140090505453253,true,140090505453253)
lkup = (symbol(&quot;???&quot;),symbol(&quot;???&quot;),4199667,true,4199667)
lkup = (:println,symbol(&quot;./string.jl&quot;),0,false,0)"><pre class="notranslate"><code class="notranslate">julia&gt; bt = backtrace()
22-element Array{Ptr{Void},1}:
 Ptr{Void} @0x00007f695d467c85
 Ptr{Void} @0x00007f695d467ce0
 Ptr{Void} @0x00007f694d567010
 Ptr{Void} @0x00007f694d567030
 Ptr{Void} @0x00007f695d41aa66
 Ptr{Void} @0x00007f695d461598
 Ptr{Void} @0x00007f695d460b0f
 Ptr{Void} @0x00007f695d460901
 Ptr{Void} @0x00007f695d461b9a
 Ptr{Void} @0x00007f695d4600e8
 Ptr{Void} @0x00007f695d472567
 Ptr{Void} @0x00007f695d4228a6
 Ptr{Void} @0x00007f695ec314c6
 Ptr{Void} @0x00007f695ec315f7
 Ptr{Void} @0x00007f695d41a9da
 Ptr{Void} @0x00007f695ec980cf
 Ptr{Void} @0x00007f695d467b27
 Ptr{Void} @0x00007f695d466abf
 Ptr{Void} @0x00000000004014bd
 Ptr{Void} @0x00007f695cd05ec5
 Ptr{Void} @0x00000000004014f3
 Ptr{Void} @0x0000000000000000

julia&gt; for l in bt
           lkup = ccall(:jl_lookup_code_address, Any, (Ptr{Void},), l)
           @show lkup
       end
lkup = (symbol("???"),symbol("???"),140090513194117,true,140090513194117)
lkup = (symbol("???"),symbol("???"),140090513194208,true,140090513194208)
lkup = (symbol("???"),symbol("???"),140090245804048,true,140090245804048)
lkup = (symbol("???"),symbol("???"),140090245804080,true,140090245804080)
lkup = (symbol("???"),symbol("???"),140090512878182,true,140090512878182)
lkup = (symbol("???"),symbol("???"),140090513167768,true,140090513167768)
lkup = (symbol("???"),symbol("???"),140090513165071,true,140090513165071)
lkup = (symbol("???"),symbol("???"),140090513164545,true,140090513164545)
lkup = (symbol("???"),symbol("???"),140090513169306,true,140090513169306)
lkup = (symbol("???"),symbol("???"),140090513162472,true,140090513162472)
lkup = (symbol("???"),symbol("???"),140090513237351,true,140090513237351)
lkup = (symbol("???"),symbol("???"),140090512910502,true,140090512910502)
lkup = (symbol("???"),symbol("???"),140090538136774,true,140090538136774)
lkup = (symbol("???"),symbol("???"),140090538137079,true,140090538137079)
lkup = (symbol("???"),symbol("???"),140090512878042,true,140090512878042)
lkup = (symbol("???"),symbol("???"),140090538557647,true,140090538557647)
lkup = (symbol("???"),symbol("???"),140090513193767,true,140090513193767)
lkup = (symbol("???"),symbol("???"),140090513189567,true,140090513189567)
lkup = (symbol("???"),symbol("???"),4199613,true,4199613)
lkup = (symbol("???"),symbol("???"),140090505453253,true,140090505453253)
lkup = (symbol("???"),symbol("???"),4199667,true,4199667)
lkup = (:println,symbol("./string.jl"),0,false,0)
</code></pre></div>
<p dir="auto">This happened with builds for <a href="https://github.com/Keno/Cxx.jl">https://github.com/Keno/Cxx.jl</a>.</p>
<p dir="auto">Backtraces are somewhat of a mess on 3.5 for a variety of reasons, including that we currently have no way to get the proper load address of a section. To verify, try e.g.:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="julia&gt; sqrt(-1)
ERROR: DomainError"><pre class="notranslate"><code class="notranslate">julia&gt; sqrt(-1)
ERROR: DomainError
</code></pre></div>
<p dir="auto">and note the missing backtrace.</p>