checking whether your assembler supports .ident directive... yes
checking for GNU non-executable stack support... no
checking for a working context diff... diff -U 1
checking for a BSD-compatible install... /usr/bin/install -c
checking for ar... /usr/bin/ar
checking whether /usr/bin/ar is GNU ar... yes
checking for ar arguments... q
checking whether /usr/bin/ar supports @file... yes
checking for ranlib... ranlib
checking whether ln -s works... yes
checking for gsed... no
checking for sed... /bin/sed
checking for time... /usr/bin/time
checking for gnutar... no
checking for gtar... no
checking for tar... /bin/tar
checking for gpatch... no
checking for patch... /usr/bin/patch
checking for dtrace... no
checking for HsColour... no
checking for xmllint... no
configure: WARNING: cannot find xmllint in your PATH, you will not be able to validate your documentation
checking for xsltproc... no
configure: WARNING: cannot find xsltproc in your PATH, you will not be able to build the HTML documentation
checking for dblatex... no
configure: WARNING: cannot find dblatex in your PATH, you will not be able to build the PDF and PS documentation
checking for ghc-pkg matching /usr/bin/ghc... /usr/bin/ghc-pkg
checking for happy... /usr/bin/happy
checking for version of happy... 1.18.9
configure: error: Happy version 1.19 or later is required to compile GHC.