Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: birch-beer-0.4.2.1 (user goal)
[__1] trying: spectral-clustering-0.3.2.2 (dependency of birch-beer)
[__2] trying: hmatrix-svdlibc-0.5.0.1 (dependency of spectral-clustering)
[__3] next goal: hmatrix (dependency of spectral-clustering)
[__3] rejecting: hmatrix-0.20.2 (conflict: hmatrix-svdlibc => hmatrix>=0.17 &&
<0.20)
[__3] skipping: hmatrix-0.20.1, hmatrix-0.20.0.0 (has the same characteristics
that caused the previous version to fail: excluded by constraint '>=0.17 &&
<0.20' from 'hmatrix-svdlibc')
[__3] trying: hmatrix-0.19.0.0
[__4] next goal: base (dependency of birch-beer)
[__4] rejecting: base-4.16.3.0/installed-4.16.3.0 (conflict: hmatrix =>
base>=4.9 && <4.15)
[__4] skipping: base-4.17.0.0, base-4.16.3.0, base-4.16.2.0, base-4.16.1.0,
base-4.16.0.0, base-4.15.1.0, base-4.15.0.0 (has the same characteristics that
caused the previous version to fail: excluded by constraint '>=4.9 && <4.15'
from 'hmatrix')
[__4] rejecting: base-4.14.3.0, base-4.14.2.0, base-4.14.1.0, base-4.14.0.0,
base-4.13.0.0, base-4.12.0.0, base-4.11.1.0, base-4.11.0.0, base-4.10.1.0,
base-4.10.0.0, base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0,
base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1,
base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0,
base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0,
base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from
non-upgradeable package requires installed instance)
[__4] fail (backjumping, conflict set: base, birch-beer, hmatrix)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: hmatrix, base, spectral-clustering,
hmatrix-svdlibc, birch-beer
Try running with --minimize-conflict-set to improve the error message.