avoid destroying error in try/finally of mktemp

it's very common for this `rm` to fail on Windows

base/file.jl

@@ -547,8 +547,13 @@ function mktemp(fn::Function, parent=tempdir())
  try
  fn(tmp_path, tmp_io)
  finally
- close(tmp_io)
- rm(tmp_path)
+ # TODO: should we call GC.gc() first on error, to make it much more likely that `rm` succeeds?
+ try
+ close(tmp_io)
+ rm(tmp_path)
+ catch ex
+ @error "mktemp cleanup" _group=:file exception=(ex, catch_backtrace())
+ end
  end
 end
 
@@ -563,7 +568,12 @@ function mktempdir(fn::Function, parent=tempdir())
  try
  fn(tmpdir)
  finally
- rm(tmpdir, recursive=true)
+ # TODO: should we call GC.gc() first on error, to make it much more likely that `rm` succeeds?
+ try
+ rm(tmpdir, recursive=true)
+ catch ex
+ @error "mktempdir cleanup" _group=:file exception=(ex, catch_backtrace())
+ end
  end
 end