thodg/libgit2

diff --git a/src/blob.c b/src/blob.c
index 5e3c22f..9871693 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -62,7 +62,7 @@ int git_blob_create_frombuffer(git_oid *oid, git_repository *repo, const void *b
 	git_odb_stream *stream;
 
 	if ((error = git_odb_open_wstream(&stream, repo->db, len, GIT_OBJ_BLOB)) < GIT_SUCCESS)
-		return error;
+		return git__rethrow(error, "Failed to create blob. Can't open write stream");
 
 	stream->write(stream, buffer, len);
 
@@ -81,7 +81,7 @@ int git_blob_create_fromfile(git_oid *oid, git_repository *repo, const char *pat
 	git_odb_stream *stream;
 
 	if (repo->path_workdir == NULL)
-		return GIT_ENOTFOUND;
+		return git__throw(GIT_ENOTFOUND, "Failed to create blob. No workdir given");
 
 	git__joinpath(full_path, repo->path_workdir, path);
 
@@ -106,7 +106,7 @@ int git_blob_create_fromfile(git_oid *oid, git_repository *repo, const char *pat
 		if (read_len < 0) {
 			gitfo_close(fd);
 			stream->free(stream);
-			return GIT_EOSERR;
+			return git__throw(GIT_EOSERR, "Failed to create blob. Can't read full file");
 		}
 
 		stream->write(stream, buffer, read_len);
diff --git a/src/revwalk.c b/src/revwalk.c
index 7879848..a32a16e 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -210,7 +210,7 @@ static int commit_quick_parse(git_revwalk *walk, commit_object *commit, git_rawo
 		git_oid oid;
 
 		if (git_oid_mkstr(&oid, (char *)buffer + STRLEN("parent ")) < GIT_SUCCESS)
-			return GIT_EOBJCORRUPTED;
+			return git__throw(GIT_EOBJCORRUPTED, "Failed to parse commit. Parent object is corrupted");
 
 		commit->parents[i] = commit_lookup(walk, &oid);
 		if (commit->parents[i] == NULL)
@@ -222,14 +222,14 @@ static int commit_quick_parse(git_revwalk *walk, commit_object *commit, git_rawo
 	commit->out_degree = (unsigned short)parents;
 
 	if ((buffer = memchr(buffer, '\n', buffer_end - buffer)) == NULL)
-		return GIT_EOBJCORRUPTED;
+		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse commit. Object is corrupted");
 
 	buffer = memchr(buffer, '>', buffer_end - buffer);
 	if (buffer == NULL)
-		return GIT_EOBJCORRUPTED;
+		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse commit. Can't find author");
 
 	if (git__strtol32(&commit_time, (char *)buffer + 2, NULL, 10) < GIT_SUCCESS)
-		return GIT_EOBJCORRUPTED;
+		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse commit. Can't parse commit time");
 
 	commit->time = (time_t)commit_time;
 	commit->parsed = 1;
@@ -245,11 +245,11 @@ static int commit_parse(git_revwalk *walk, commit_object *commit)
 		return GIT_SUCCESS;
 
 	if ((error = git_odb_read(&obj, walk->repo->db, &commit->oid)) < GIT_SUCCESS)
-		return error;
+		return git__rethrow(error, "Failed to parse commit. Can't read object");
 
 	if (obj->raw.type != GIT_OBJ_COMMIT) {
 		git_odb_object_close(obj);
-		return GIT_EOBJTYPE;
+		return git__throw(GIT_EOBJTYPE, "Failed to parse commit. Object is no commit object");
 	}
 
 	error = commit_quick_parse(walk, commit, &obj->raw);
@@ -305,7 +305,7 @@ static int push_commit(git_revwalk *walk, const git_oid *oid, int uninteresting)
 
 	commit = commit_lookup(walk, oid);
 	if (commit == NULL)
-		return GIT_ENOTFOUND;
+		return git__throw(GIT_ENOTFOUND, "Failed to push commit. Object not found");
 
 	commit->uninteresting = uninteresting;
 
@@ -349,7 +349,7 @@ static int revwalk_next_timesort(commit_object **object_out, git_revwalk *walk)
 		}
 	}
 
-	return GIT_EREVWALKOVER;
+	return git__throw(GIT_EREVWALKOVER, "No more commits left to iterate");
 }
 
 static int revwalk_next_unsorted(commit_object **object_out, git_revwalk *walk)
@@ -367,7 +367,7 @@ static int revwalk_next_unsorted(commit_object **object_out, git_revwalk *walk)
 		}
 	}
 
-	return GIT_EREVWALKOVER;
+	return git__throw(GIT_EREVWALKOVER, "No more commits left to iterate");
 }
 
 static int revwalk_next_toposort(commit_object **object_out, git_revwalk *walk)
@@ -378,7 +378,7 @@ static int revwalk_next_toposort(commit_object **object_out, git_revwalk *walk)
 	for (;;) {
 		next = commit_list_pop(&walk->iterator_topo);
 		if (next == NULL)
-			return GIT_EREVWALKOVER;
+			return git__throw(GIT_EREVWALKOVER, "No more commits left to iterate");
 
 		if (next->in_degree > 0) {
 			next->topo_delay = 1;
diff --git a/src/tree.c b/src/tree.c
index b7daf39..6f9fc86 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -151,15 +151,15 @@ static int tree_parse_buffer(git_tree *tree, const char *buffer, const char *buf
 			return GIT_ENOMEM;
 
 		if (git__strtol32((long *)&entry->attr, buffer, &buffer, 8) < GIT_SUCCESS)
-			return GIT_EOBJCORRUPTED;
+			return git__throw(GIT_EOBJCORRUPTED, "Failed to parse tree. Can't parse attributes");
 
 		if (*buffer++ != ' ') {
-			error = GIT_EOBJCORRUPTED;
+			error = git__throw(GIT_EOBJCORRUPTED, "Failed to parse tree. Object it corrupted");
 			break;
 		}
 
 		if (memchr(buffer, 0, buffer_end - buffer) == NULL) {
-			error = GIT_EOBJCORRUPTED;
+			error = git__throw(GIT_EOBJCORRUPTED, "Failed to parse tree. Object it corrupted");
 			break;
 		}
 
@@ -274,7 +274,7 @@ int git_tree_create_fromindex(git_oid *oid, git_index *index)
 	int error;
 
 	if (index->repository == NULL)
-		return GIT_EBAREINDEX;
+		return git__throw(GIT_EBAREINDEX, "Failed to create tree. The index file is not backed up by an existing repository");
 
 	error = write_index(oid, index, "", 0, 0, git_index_entrycount(index));
 	return (error < GIT_SUCCESS) ? error : GIT_SUCCESS;
@@ -343,7 +343,7 @@ int git_treebuilder_insert(git_tree_entry **entry_out, git_treebuilder *bld, con
 	assert(bld && id && filename);
 
 	if (!valid_attributes(attributes))
-		return GIT_ERROR;
+		return git__throw(GIT_ERROR, "Failed to insert entry. Invalid atrributes");
 
 	if ((pos = git_vector_bsearch2(&bld->entries, entry_search_cmp, filename)) != GIT_ENOTFOUND) {
 		entry = git_vector_get(&bld->entries, pos);
@@ -400,7 +400,7 @@ int git_treebuilder_remove(git_treebuilder *bld, const char *filename)
 	git_tree_entry *remove_ptr = (git_tree_entry *)git_treebuilder_get(bld, filename);
 
 	if (remove_ptr == NULL || remove_ptr->removed)
-		return GIT_ENOTFOUND;
+		return git__throw(GIT_ENOTFOUND, "Failed to remove entry. File isn't in the tree");
 
 	remove_ptr->removed = 1;
 	bld->entry_count--;
@@ -431,7 +431,7 @@ int git_treebuilder_write(git_oid *oid, git_repository *repo, git_treebuilder *b
 	}
 
 	if ((error = git_odb_open_wstream(&stream, git_repository_database(repo), size, GIT_OBJ_TREE)) < GIT_SUCCESS)
-		return error;
+		return git__rethrow(error, "Failed to write tree. Can't open write stream");
 
 	for (i = 0; i < bld->entries.length; ++i) {
 		git_tree_entry *entry = bld->entries.contents[i];
diff --git a/src/vector.c b/src/vector.c
index d0b0c5c..1ddc26e 100644
--- a/src/vector.c
+++ b/src/vector.c
@@ -106,7 +106,7 @@ int git_vector_bsearch2(git_vector *v, git_vector_cmp key_lookup, const void *ke
 
 	/* need comparison function to sort the vector */
 	if (v->_cmp == NULL)
-		return GIT_ENOTFOUND;
+		return git__throw(GIT_ENOTFOUND, "Can't sort vector. No comparison function set");
 
 	git_vector_sort(v);
 
@@ -114,7 +114,7 @@ int git_vector_bsearch2(git_vector *v, git_vector_cmp key_lookup, const void *ke
 	if (find != NULL)
 		return (int)(find - v->contents);
 
-	return GIT_ENOTFOUND;
+	return git__throw(GIT_ENOTFOUND, "Can't find element");
 }
 
 int git_vector_search2(git_vector *v, git_vector_cmp key_lookup, const void *key)
@@ -128,7 +128,7 @@ int git_vector_search2(git_vector *v, git_vector_cmp key_lookup, const void *key
 			return i;
 	}
 
-	return GIT_ENOTFOUND;
+	return git__throw(GIT_ENOTFOUND, "Can't find element");
 }
 
 static int strict_comparison(const void *a, const void *b)
@@ -143,9 +143,6 @@ int git_vector_search(git_vector *v, const void *entry)
 
 int git_vector_bsearch(git_vector *v, const void *key)
 {
-	if (v->_cmp == NULL)
-		return GIT_ENOTFOUND;
-
 	return git_vector_bsearch2(v, v->_cmp, key);
 }
 
@@ -156,7 +153,7 @@ int git_vector_remove(git_vector *v, unsigned int idx)
 	assert(v);
 
 	if (idx >= v->length || v->length == 0)
-		return GIT_ENOTFOUND;
+		return git__throw(GIT_ENOTFOUND, "Can't remove element. Index out of bounds");
 
 	for (i = idx; i < v->length - 1; ++i)
 		v->contents[i] = v->contents[i + 1];