Index: os-prober/common.sh

===================================================================

--- os-prober.orig/common.sh

+++ os-prober/common.sh

@@ -62,10 +62,14 @@ cache_progname() {

   esac

 }

-log() {

-  cache_progname

-  logger -t "$progname" "$@"

-}

+# fd_logger: bind value now, possibly after assigning default. 

+eval '

+  log() {

+    cache_progname

+    echo "$progname: $@"  1>&'${fd_logger:=9}'

+  }

+'

+export fd_logger  # so subshells inherit current value by default

 error() {

   log "error: $@"

@@ -81,10 +85,14 @@ debug() {

   fi

 }

-result () {

-  log "result:" "$@"

-  echo "$@"

-}

+# fd_result: bind value now, possibly after assigning default.

+eval '

+  result() {

+    log "result:" "$@"

+    echo "$@"  1>&'${fd_result:=1}'

+  }

+'

+export fd_result  # so subshells inherit current value by default

 # shim to make it easier to use os-prober outside d-i

 if ! type mapdevfs >/dev/null 2>&1; then

Index: os-prober/linux-boot-prober

===================================================================

--- os-prober.orig/linux-boot-prober

+++ os-prober/linux-boot-prober

@@ -1,4 +1,12 @@

 #!/bin/sh

+

+# dash shell does not have "{varname}>&1" feature that bash shell has

+# for auto-assignment of new filedescriptors.

+# It is cumbersome to write the 'eval' to use our own variables in redirections.

+# Therefore use fixed numbers.

+export fd_result=3  # file descriptor for external results

+export fd_logger=9  # file descriptor for input to logger

+

 . /usr/share/os-prober/common.sh

 set -e

@@ -19,6 +27,7 @@ bootuuid=

 grep "^/dev/" /proc/mounts | parse_proc_mounts >"$OS_PROBER_TMP/mounted-map" || true

+( (

 if [ -z "$1" ]; then

 	ERR=y

 elif [ "$1" = btrfs -a -z "$2" ]; then

@@ -186,3 +195,5 @@ else

 		fi

 	fi

 fi

+) 9>&1 | logger 1>&-  # fd_logger

+) 3>&1  # fd_result

Index: os-prober/os-prober

===================================================================

--- os-prober.orig/os-prober

+++ os-prober/os-prober

@@ -1,7 +1,14 @@

 #!/bin/sh

 set -e

-. /usr/share/os-prober/common.sh

+# dash shell does not have "{varname}>&1" feature that bash shell has

+# for auto-assignment of new filedescriptors.

+# It is cumbersome to write the 'eval' to use our own variables in redirections.

+# Therefore use fixed numbers.

+export fd_result=3  # file descriptor for external results

+export fd_logger=9  # file descriptor for input to logger

+

+ . /usr/share/os-prober/common.sh

 newns "$@"

 require_tmpdir

@@ -136,6 +143,7 @@ fi

 : >"$OS_PROBER_TMP/btrfs-vols"

+( (

 for partition in $(partitions); do

 	if ! mapped="$(mapdevfs "$partition")"; then

 		log "Device '$partition' does not exist; skipping"

@@ -200,3 +208,5 @@ for partition in $(partitions); do

 		fi

 	fi

 done

+) 9>&1 | logger 1>&-  # fd_logger

+) 3>&1  # fd_result