* Sync with the trunk.

src/libexpr/eval.cc

@@ -59,6 +59,7 @@ std::ostream & operator << (std::ostream & str, const Value & v)
         str << "]";
         break;
     case tThunk:
+    case tApp:
     case tCopy:
         str << "<CODE>";
         break;
@@ -901,12 +902,18 @@ string EvalState::forceString(Value & v)
 }
 
 
-string EvalState::forceString(Value & v, PathSet & context)
+void copyContext(const Value & v, PathSet & context)
 {
-    string s = forceString(v);
     if (v.string.context)
         for (const char * * p = v.string.context; *p; ++p) 
             context.insert(*p);
+}
+
+
+string EvalState::forceString(Value & v, PathSet & context)
+{
+    string s = forceString(v);
+    copyContext(v, context);
     return s;
 }
 
@@ -937,9 +944,7 @@ string EvalState::coerceToString(Value & v, PathSet & context,
     string s;
 
     if (v.type == tString) {
-        if (v.string.context) 
-            for (const char * * p = v.string.context; *p; ++p) 
-                context.insert(*p);
+        copyContext(v, context);
         return v.string.s;
     }
 

src/libexpr/eval.hh

@@ -163,6 +163,8 @@ void mkString(Value & v, const char * s);
 void mkString(Value & v, const string & s, const PathSet & context = PathSet());
 void mkPath(Value & v, const char * s);
 
+void copyContext(const Value & v, PathSet & context);
+
 
 typedef std::map<Path, Hash> DrvHashes;
 

src/libexpr/nixexpr.hh

@@ -15,6 +15,7 @@ MakeError(AssertionError, EvalError)
 MakeError(ThrownError, AssertionError)
 MakeError(Abort, EvalError)
 MakeError(TypeError, EvalError)
+MakeError(ImportError, EvalError) // error building an imported derivation
 
 
 /* Position objects. */

src/libexpr/primops.cc

@@ -37,7 +37,11 @@ static void prim_import(EvalState & state, Value * * args, Value & v)
             throw EvalError(format("cannot import `%1%', since path `%2%' is not valid")
                 % path % *i);
         if (isDerivation(*i))
+            try {
                 store->buildDerivations(singleton<PathSet>(*i));
+            } catch (Error & e) {
+                throw ImportError(e.msg());
+            }
     }
 
     state.evalFile(path, v);

src/libexpr/value-to-xml.cc

@@ -69,6 +69,7 @@ static void printValueAsXML(EvalState & state, bool strict, bool location,
 
         case tString:
             /* !!! show the context? */
+            copyContext(v, context);
             doc.writeEmptyElement("string", singletonAttrs("value", v.string.s));
             break;
 

src/libstore/build.cc

@@ -267,7 +267,7 @@ public:
 
 
 MakeError(SubstError, Error)
-MakeError(BuildError, Error) /* denoted a permanent build failure */
+MakeError(BuildError, Error) /* denotes a permanent build failure */
 
 
 //////////////////////////////////////////////////////////////////////

src/libstore/local-store.cc

@@ -1036,6 +1036,8 @@ void LocalStore::exportPath(const Path & path, bool sign,
         writeInt(1, hashAndWriteSink);
         
         Path tmpDir = createTempDir();
+        PathLocks tmpDirLock(singleton<PathSet, Path>(tmpDir));
+        tmpDirLock.setDeletion(true);
         AutoDelete delTmp(tmpDir);
         Path hashFile = tmpDir + "/hash";
         writeFile(hashFile, printHash(hash));
@@ -1085,6 +1087,8 @@ Path LocalStore::importPath(bool requireSignature, Source & source)
        store path follows the archive data proper), and besides, we
        don't know yet whether the signature is valid. */
     Path tmpDir = createTempDir(nixStore);
+    PathLocks tmpDirLock(singleton<PathSet, Path>(tmpDir));
+    tmpDirLock.setDeletion(true);
     AutoDelete delTmp(tmpDir); /* !!! could be GC'ed! */
     Path unpacked = tmpDir + "/unpacked";
 

src/libstore/optimise-store.cc

@@ -119,9 +119,23 @@ static void hashAndLink(bool dryRun, HashToPath & hashToPath,
             }
 
             /* Atomically replace the old file with the new hard link. */
-            if (rename(tempLink.c_str(), path.c_str()) == -1)
+            if (rename(tempLink.c_str(), path.c_str()) == -1) {
+                if (errno == EMLINK) {
+                    /* Some filesystems generate too many links on the
+                       rename, rather than on the original link.
+                       (Probably it temporarily increases the st_nlink
+                       field before decreasing it again.) */
+                    printMsg(lvlInfo, format("`%1%' has maximum number of links") % prevPath.first);
+                    hashToPath[hash] = std::pair<Path, ino_t>(path, st.st_ino);
+
+                    /* Unlink the temp link. */
+                    if (unlink(tempLink.c_str()) == -1)
+                        printMsg(lvlError, format("unable to unlink `%1%'") % tempLink);
+                    return;
+                }
                 throw SysError(format("cannot rename `%1%' to `%2%'")
                     % tempLink % path);
+            }
         } else
             printMsg(lvlTalkative, format("would link `%1%' to `%2%'") % path % prevPath.first);
         

src/libstore/store-api.hh

@@ -16,8 +16,6 @@ namespace nix {
 typedef std::map<Path, Path> Roots;
 
 
-
-
 struct GCOptions
 {
     /* Garbage collector operation:

src/nix-env/user-env.cc

@@ -106,8 +106,6 @@ bool createUserEnv(EvalState & state, DrvInfos & elems,
     Path manifestFile = store->addTextToStore("env-manifest.nix",
         (format("%1%") % manifest).str(), references);
 
-    printMsg(lvlError, manifestFile);
-
     /* Get the environment builder expression. */
     Value envBuilder;
     state.eval(parseExprFromFile(state, nixDataDir + "/nix/corepkgs/buildenv"), envBuilder);

src/nix-store/Makefile.am

@@ -1,6 +1,9 @@
 bin_PROGRAMS = nix-store
 
-nix_store_SOURCES = nix-store.cc dotgraph.cc dotgraph.hh help.txt
+nix_store_SOURCES =				\
+  nix-store.cc dotgraph.cc dotgraph.hh help.txt	\
+  xmlgraph.cc xmlgraph.hh
+
 nix_store_LDADD = ../libmain/libmain.la ../libstore/libstore.la ../libutil/libutil.la \
  ../boost/format/libformat.la
 

src/nix-store/dotgraph.cc

@@ -52,13 +52,13 @@ static string symbolicName(const string & path)
 }
 
 
+#if 0
 string pathLabel(const Path & nePath, const string & elemPath)
 {
     return (string) nePath + "-" + elemPath;
 }
 
 
-#if 0
 void printClosure(const Path & nePath, const StoreExpr & fs)
 {
     PathSet workList(fs.closure.roots);

src/nix-store/help.txt

@@ -42,6 +42,7 @@ Query flags:
   --referrers-closure: print all paths (in)directly refering to the path
   --tree: print a tree showing the dependency graph of the path
   --graph: print a dot graph rooted at given path
+  --xml: emit an XML representation of the graph rooted at the given path
   --hash: print the SHA-256 hash of the contents of the path
   --roots: print the garbage collector roots that point to the path
 

src/nix-store/nix-store.cc

@@ -6,6 +6,7 @@
 #include "archive.hh"
 #include "shared.hh"
 #include "dotgraph.hh"
+#include "xmlgraph.hh"
 #include "local-store.hh"
 #include "util.hh"
 #include "help.txt.hh"
@@ -226,7 +227,7 @@ static void opQuery(Strings opFlags, Strings opArgs)
 {
     enum { qOutputs, qRequisites, qReferences, qReferrers
          , qReferrersClosure, qDeriver, qBinding, qHash
-         , qTree, qGraph, qResolve, qRoots } query = qOutputs;
+         , qTree, qGraph, qXml, qResolve, qRoots } query = qOutputs;
     bool useOutput = false;
     bool includeOutputs = false;
     bool forceRealise = false;
@@ -249,6 +250,7 @@ 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 == "--xml") query = qXml;
         else if (*i == "--resolve") query = qResolve;
         else if (*i == "--roots") query = qRoots;
         else if (*i == "--use-output" || *i == "-u") useOutput = true;
@@ -331,6 +333,14 @@ static void opQuery(Strings opFlags, Strings opArgs)
             break;
         }
 
+        case qXml: {
+            PathSet roots;
+            foreach (Strings::iterator, i, opArgs)
+                roots.insert(maybeUseOutput(followLinksToStorePath(*i), useOutput, forceRealise));
+            printXmlGraph(roots);
+            break;
+        }
+
         case qResolve: {
             foreach (Strings::iterator, i, opArgs)
                 cout << format("%1%\n") % followLinksToStorePath(*i);

src/nix-store/xmlgraph.cc

@@ -0,0 +1,71 @@
+#include "xmlgraph.hh"
+#include "util.hh"
+#include "store-api.hh"
+
+#include <iostream>
+
+
+using std::cout;
+
+namespace nix {
+
+
+static inline const string & xmlQuote(const string & s)
+{
+    // Luckily, store paths shouldn't contain any character that needs to be
+    // quoted.
+    return s;
+}
+
+
+static string makeEdge(const string & src, const string & dst)
+{
+    format f = format("  <edge src=\"%1%\" dst=\"%2%\"/>\n")
+      % xmlQuote(src) % xmlQuote(dst);
+    return f.str();
+}
+
+
+static string makeNode(const string & id)
+{
+    format f = format("  <node name=\"%1%\"/>\n") % xmlQuote(id);
+    return f.str();
+}
+
+
+void printXmlGraph(const PathSet & roots)
+{
+    PathSet workList(roots);
+    PathSet doneSet;
+
+    cout << "<?xml version='1.0' encoding='utf-8'?>\n"
+	 << "<nix>\n";
+
+    while (!workList.empty()) {
+	Path path = *(workList.begin());
+	workList.erase(path);
+
+	if (doneSet.find(path) != doneSet.end()) continue;
+	doneSet.insert(path);
+
+	cout << makeNode(path);
+
+	PathSet references;
+	store->queryReferences(path, references);
+
+	for (PathSet::iterator i = references.begin();
+	     i != references.end(); ++i)
+	{
+	    if (*i != path) {
+		workList.insert(*i);
+		cout << makeEdge(*i, path);
+	    }
+	}
+
+    }
+
+    cout << "</nix>\n";
+}
+
+
+}

src/nix-store/xmlgraph.hh

@@ -0,0 +1,12 @@
+#ifndef __XMLGRAPH_H
+#define __XMLGRAPH_H
+
+#include "types.hh"
+
+namespace nix {
+
+void printXmlGraph(const PathSet & roots);
+
+}
+
+#endif /* !__XMLGRAPH_H */