Finding dependency cycles

[Danny Milosavljevic]

Hi,

so I'm trying to untangle the matplotlib -> ipython dependency cycle.

Unfortunately, guix error message isn't really helpful in finding out what it 
was.

It says


guix/base32.scm:104:4: In procedure #<procedure 1945860 at 
guix/base32.scm:104:4 (bv index)>:
guix/base32.scm:104:4: Throw to key `vm-error' with args `(vm-run "VM: Stack 
overflow" ())'.
Backtrace:
In guix/packages.scm:
 838: 19 [expand-input # # # ...]
 793: 18 [cache! #<weak-key-hash-table 1bac820 474/883> # # ...]
1097: 17 [thunk]
1029: 16 [bag->derivation # # #]
In srfi/srfi-1.scm:
 578: 15 [map #<procedure 4468180 at guix/packages.scm:1031:30 (t-1108537)> #]
In guix/packages.scm:
 853: 14 [expand-input # # # ...]
In guix/store.scm:
1182: 13 [run-with-store # ...]
In guix/packages.scm:
1199: 12 [#<procedure 61afb40 at guix/packages.scm:1199:5 (state)> #]
In guix/gexp.scm:
 582: 11 [#<procedure 4472420 at guix/gexp.scm:582:2 (state)> #]
In guix/store.scm:
1105: 10 [#<procedure 4477ed0 at guix/store.scm:1104:28 (store)> #]
In guix/derivations.scm:
 842: 9 [derivation #<build-daemon 256.15 21dcb40> "module-import" ...]
 740: 8 [add-output-paths #<derivation #f =>  62e6460>]
In srfi/srfi-1.scm:
 578: 7 [map #<procedure 4477c00 at guix/derivations.scm:741:29 (expr)> (#)]
In guix/derivations.scm:
 744: 6 [#<procedure 4477c00 at guix/derivations.scm:741:29 (expr)> ("out" . #)]
 669: 5 [store-path "output:out" ...]
In guix/base32.scm:
 142: 4 [#<procedure 14807b0 at guix/base32.scm:140:2 (bv)> #vu8(120 134 169 
141 131 9 168 9 255 14 95 77 50 123 239 139 107 100 105 6)]
 137: 3 [bytevector-quintet-fold-right #<procedure 67527c0 at 
guix/base32.scm:142:31 (q r)> ...]
 104: 2 [#<procedure 1945860 at guix/base32.scm:104:4 (bv index)> #vu8(120 134 
169 141 131 9 168 9 255 14 95 77 50 123 239 139 107 100 105 6) ...]
In ice-9/boot-9.scm:
 105: 1 [#<procedure 137b180 at ice-9/boot-9.scm:97:6 (thrown-k . args)> 
vm-error ...]
  65: 0 [abort-to-prompt catch7 vm-error vm-run "VM: Stack overflow" ()]

ice-9/boot-9.scm:65:2: In procedure abort-to-prompt:
ice-9/boot-9.scm:65:2: Throw to key `vm-error' with args `(vm-run "VM: Stack 
overflow" ())'.

.

Is there a way to improve this error message? Alternatively, is there a command 
to manually find the problem?