use cabal-link-bins in cabal-install-exec

Also fix TODO in cabal-install-exec: avoid package downloaded being
uninstallable according to Stackage LTS downloaded

2 files changed, 12 insertions, 20 deletions

diff --git a/.shenv b/.shenv
index f39d9d2e..00f1c83a 100755
--- a/.shenv
+++ b/.shenv
@@ -58,14 +58,6 @@ addition="$HOME/.cabal/bin";                      maybe_add_to_path
 addition="$HOME/.local/bin";                      maybe_add_to_path
 addition="/meta/s/spw/local/src/git-annex.linux"; maybe_add_to_path
 
-# now add places where there might be an exe made by cabal-install
-for bindir in $(find ~/local/src -path "*/.cabal-sandbox/bin"); do
-    addition="$bindir";                           maybe_add_to_path
-done
-for bindir in $(find ~/src -path "*/.cabal-sandbox/bin"); do
-    addition="$bindir";                           maybe_add_to_path
-done
-
 unset addition
 export PATH
 
diff --git a/bin/cabal-install-exec b/bin/cabal-install-exec
index fd534362..deebdf5c 100755
--- a/bin/cabal-install-exec
+++ b/bin/cabal-install-exec
@@ -1,16 +1,16 @@
 #!/bin/sh
 
-# TODO need to put cabal.config constraints in before downloading or
-# the version that `cabal get` installs might not itself be
-# installable
-mkdir -p $HOME/local/src
+cabal --no-require-sandbox update
 for var in "$@"; do
-    cd $HOME/local/src
-    cabal get $var
-    cd ${var}*
-    touch .duplicity-ignore
-    wget https://www.stackage.org/lts/cabal.config
-    cabal sandbox init
-    cabal update
-    cabal install
+    if [ -d "$HOME/local/src/${var}"]; then
+        echo >&2 "$(basename $0): a version of $var is already installed; skipping"
+    else
+        mkdir -p $HOME/local/src/${var}
+        cd $HOME/local/src/${var}
+        touch .duplicity-ignore
+        cabal sandbox init
+        wget https://www.stackage.org/lts/cabal.config
+        cabal install $var
+        cabal-link-bins
+    fi
 done