Fix unmounting folders.

scripts/build_image/build_alpine.bash

@@ -7,13 +7,18 @@ DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 ############## Setup #########################
 
 function cleanup {
+    sync
+    for f in "${gpgagents[@]}"; do
+        >&2 echo "Killing gpg-agent $f"
+        GNUPGHOME="$f" gpgconf --kill gpg-agent
+    done
     for f in "${jails[@]}"; do
         >&2 echo "Stopping jail $f"
         jail -r "$f"
     done
     for (( idx=${#mountedfolders[@]}-1 ; idx>=0 ; idx-- )) ; do
         >&2 echo "Unmounting folder ${mountedfolders[idx]}"
-        umount "${mountedfolders[idx]}"
+        umount -f "${mountedfolders[idx]}"
     done
     for f in "${memorydevices[@]}"; do
         >&2 echo "Removing memory device $f"
@@ -28,6 +33,7 @@ folders=()
 jails=()
 memorydevices=()
 mountedfolders=()
+gpgagents=()
 for sig in EXIT INT QUIT HUP TERM; do
   trap "set +e; cleanup" "$sig"
 done
@@ -157,8 +163,11 @@ function download_alpine {
     sha256 -c "$ALPINE_SHA256" "${download_directory}/${ALPINE_TARBALL}"
 
     local keyring="$work_directory/keyring"
-    gpg --no-default-keyring --keyring "$keyring" --trust-model always --import <<<"$ALPINE_KEY"
-    gpg --no-default-keyring --keyring "$keyring" --trust-model always --verify <(cat <<<"$ALPINE_SIGNATURE") "${download_directory}/${ALPINE_TARBALL}"
+    local gpghome="$work_directory/gpghome"
+    (umask 077 && mkdir "$gpghome")
+    GNUPGHOME="$gpghome" gpg --no-default-keyring --keyring "$keyring" --trust-model always --import <<<"$ALPINE_KEY"
+    gpgagents+=("$gpghome")
+    GNUPGHOME="$gpghome" gpg --no-default-keyring --keyring "$keyring" --trust-model always --verify <(cat <<<"$ALPINE_SIGNATURE") "${download_directory}/${ALPINE_TARBALL}"
 }
 
 function make_chroot {