lens version 3.0 does not support Control.Lens.At module. The version 3.10 is used in the example of 'cabal install' in this documentation.
Signed-off-by: Jun Futagawa <[email protected]> --- INSTALL | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/INSTALL b/INSTALL index 328d727..912ed05 100644 --- a/INSTALL +++ b/INSTALL @@ -154,7 +154,7 @@ deploy Ganeti on production machines). More specifically: - `lifted-base <http://hackage.haskell.org/package/lifted-base>`_, version 0.1.1 and above. - `lens <http://hackage.haskell.org/package/lens>`_, - version 3.0 and above. + version 3.10 and above. Some of these are also available as package in Debian/Ubuntu:: -- 1.8.3.1
