Shall we make -dsuppress-uniques default?

Richard Eisenberg rae at
Fri Oct 5 18:54:55 UTC 2018

I'm in the opposite camp. More often than not, the biggest advantage of dumps during GHC development is to see the uniques. Indeed, I often ignore the actual names of variables and just work in my head with the uniques.

Perhaps the more complete answer is to fine-tune what settings cause the uniques to be printed. -ddump-xx-trace should almost certainly. Perhaps other modes needn't. What do you say to GHC to get it to print the uniques that you don't like?


> On Oct 5, 2018, at 2:48 PM, Ömer Sinan Ağacan <omeragacan at> wrote:
> I asked this on IRC and didn't hear a lot of opposition, so as the next step
> I'd like to ask ghc-devs.
> I literally never need the details on uniques that we currently print by
> default. I either don't care about variables too much (when not comparing the
> output with some other output), or I need -dsuppress-uniques (when comparing
> outputs). The problem is I have to remember to add -dsuppress-uniques if I'm
> going to compare the outputs, and if I decide to compare outputs after the fact
> I need to re-generate them with -dsuppress-uniques. This takes time and effort.
> If you're also of the same opinion I suggest making -dsuppress-uniques default,
> and providing a -dno-suppress-uniques (if it doesn't already exist).
> Ömer
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