Excessive capistrano/cabal output

gistfile1.md

This is a subset of the output of cap production deploy. I have a simple task that compiles my app with Cabal:

namespace :deploy do
  task :compile do
    on roles(:all) do
      within release_path do
        execute 'cabal', 'update'
        execute 'cabal', 'sandbox', 'init'
        execute 'cabal', 'install', '--only-dependencies', '--force-reinstall', '--verbose=0', '-O2'
        execute 'cabal', 'build'
      end
    end
  end
end

When it runs I get thousands of lines of text; output from GHC is one character per line with other text interpolated between. The "other text" seems to be just the last piece of STDOUT to be printed before the "vertical" message, but I'm not certain of that.

gistfile2.txt

DEBUG [91c53983] 	Warning:
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	This binding for
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	`
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	e
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	o
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	f
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	'
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	shadows the existing binding
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	bound at
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983]
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	l
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	i
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	b
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	/
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	D
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	a
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	t
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	a
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	/
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	E
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	n
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	u
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	m
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	e
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	r
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	a
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	t
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	o
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	r
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	/
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	T
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	e
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	x
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	t
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	.
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	h
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	s
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	:
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	7
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	3
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	9
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	:
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	2
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h
DEBUG [91c53983] 	9
DEBUG [91c53983] 	config.status: creating include/HsUnixConfig.h