diff --git a/doc/manual/nix-pack-closure.xml b/doc/manual/nix-pack-closure.xml
index 12eacf502..030b15500 100644
--- a/doc/manual/nix-pack-closure.xml
+++ b/doc/manual/nix-pack-closure.xml
@@ -58,6 +58,14 @@ $ nix-pack-closure $(which azureus) | ssh scratchy nix-unpack-closure
+As a variation on the previous example, copy
+azureus, and also install it in the user’s profile
+on the target machine:
+
+
+$ nix-pack-closure $(which azureus) | ssh scratchy 'nix-env -i $(nix-unpack-closure)'
+
+
diff --git a/doc/manual/nix-unpack-closure.xml b/doc/manual/nix-unpack-closure.xml
index 7c6d12d08..e95225e81 100644
--- a/doc/manual/nix-unpack-closure.xml
+++ b/doc/manual/nix-unpack-closure.xml
@@ -22,6 +22,12 @@ closure is a single file read from standard input. See the
description of nix-pack-closure for details and
examples.
+The top-level paths in the closure (i.e., the paths passed to
+the original nix-pack-closure call that created the
+closure) are printed on standard output. These paths can be passed,
+for instance, to nix-env -i to install them into a
+user environment on the target machine.
+
diff --git a/scripts/nix-pack-closure.in b/scripts/nix-pack-closure.in
index 6c0e85d2a..bc58097e2 100644
--- a/scripts/nix-pack-closure.in
+++ b/scripts/nix-pack-closure.in
@@ -21,6 +21,7 @@ mkdir "$tmpDir/contents", 0777 or die;
mkdir "$tmpDir/references", 0777 or die;
mkdir "$tmpDir/derivers", 0777 or die;
+open TOPLEVEL, ">$tmpDir/top-level" or die;
my %storePaths;
@@ -29,6 +30,12 @@ my %storePaths;
while (@ARGV) {
my $storePath = shift @ARGV;
+ # $storePath might be a symlink to the store, so resolve it.
+ $storePath = (`$binDir/nix-store --query --resolve '$storePath'`
+ or die "cannot resolve `$storePath'");
+ chomp $storePath;
+ print TOPLEVEL $storePath, "\n";
+
# Get the closure of this path.
my $pid = open(READ,
"$binDir/nix-store --query --requisites '$storePath'|") or die;
diff --git a/scripts/nix-unpack-closure.in b/scripts/nix-unpack-closure.in
index 89e7aa24d..2b60bb485 100644
--- a/scripts/nix-unpack-closure.in
+++ b/scripts/nix-unpack-closure.in
@@ -77,3 +77,12 @@ closedir(DIR) or die;
# Register the invalid paths as valid.
system("nix-store --register-validity <'$tmpDir/validity'") == 0
or die "nix-store --register-validity failed";
+
+
+# Show the top-level paths so that something useful can be done with
+# them, e.g., passing them to `nix-env -i'.
+if (-e "$tmpDir/unpacked/top-level") {
+ open TOPLEVEL, "<$tmpDir/unpacked/top-level" or die;
+ while () { print "$_"; }
+ close TOPLEVEL;
+}
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index 701e83974..f0b3f5b61 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -296,7 +296,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
{
enum { qOutputs, qRequisites, qReferences, qReferrers
, qReferrersClosure, qDeriver, qBinding, qHash
- , qTree, qGraph } query = qOutputs;
+ , qTree, qGraph, qResolve } query = qOutputs;
bool useOutput = false;
bool includeOutputs = false;
bool forceRealise = false;
@@ -320,6 +320,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
else if (*i == "--hash") query = qHash;
else if (*i == "--tree") query = qTree;
else if (*i == "--graph") query = qGraph;
+ else if (*i == "--resolve") query = qResolve;
else if (*i == "--use-output" || *i == "-u") useOutput = true;
else if (*i == "--force-realise" || *i == "-f") forceRealise = true;
else if (*i == "--include-outputs") includeOutputs = true;
@@ -410,6 +411,13 @@ static void opQuery(Strings opFlags, Strings opArgs)
break;
}
+ case qResolve: {
+ for (Strings::iterator i = opArgs.begin();
+ i != opArgs.end(); ++i)
+ cout << format("%1%\n") % fixPath(*i);
+ break;
+ }
+
default:
abort();
}