make dev-switch fails

[gares]

I'm trying to work on #3486 and following HACKING.md I tried to set up a development switch.

gares@ollypat:~/work-area/dune$ make dev-switch
opam switch create -y . --deps-only --with-test
[ERROR] Could not resolve set of base packages:
        Your request can't be satisfied:
          - No available version of ocaml-base-compiler satisfies the
        constraints


Switch initialisation failed: clean up? ('n' will leave the switch partially
installed) [Y/n] y
Makefile:47: recipe for target 'dev-switch' failed
make: *** [dev-switch] Error 20
gares@ollypat:~/work-area/dune$ opam --version
2.0.7

[ghost]

hmm, it seems to work on my machine. Not really sure what's happening. But TBH I develop on Dune using my global opam installation and it works just fine. You just need a recent enough version of the compiler and if you want to run the test suite you'll need to install a bunch of packages: ppx_expect, utop, odoc and maybe a couple of other ones

[gares]

This is what I've ended up doing, and it works for me as well.

[avsm]

Need to specify a compiler for that to be reliable, due to the more complex formula that dune has (with a secondary compiler). Try

opam switch create . 4.10.0 --deps-only --with-test

Should fix that in the dev-switch target too, I think.

[rgrinberg]

I fixed the dev-switch target with Anil's advice.