diff --git a/CI/tools.py b/CI/tools.py
index 67e28f54f..3bb2eb1e1 100644
--- a/CI/tools.py
+++ b/CI/tools.py
@@ -12,7 +12,7 @@
 
 
 MERCURIAL_VERSION = '5.3'
-GIT_VERSION = '2.26.2'
+GIT_VERSION = '2.27.0'
 
 ALL_MERCURIAL_VERSIONS = (
     '1.9.3', '2.0.2', '2.1.2', '2.2.3', '2.3.2', '2.4.2', '2.5.4',
diff --git a/cinnabar/hg/repo.py b/cinnabar/hg/repo.py
index 6b7500a54..5fab834c3 100644
--- a/cinnabar/hg/repo.py
+++ b/cinnabar/hg/repo.py
@@ -811,7 +811,8 @@ def do_cinnabarclone(repo, manifest, store):
             if not any(Git.iter(
                     'rev-list', '--branches', '--tags', '--remotes',
                     '--max-count=1', '--ancestry-path', '--stdin',
-                    stdin=(b'^%s^@' % c for c in graft))):
+                    stdin=(b'^%s^@' % c for c in graft),
+                    stderr=open(os.devnull, 'wb'))):
                 continue
 
         candidates.append((spec, len(graft) != 0))
diff --git a/cinnabar/remote_helper.py b/cinnabar/remote_helper.py
index f6e44bf54..26af646ed 100644
--- a/cinnabar/remote_helper.py
+++ b/cinnabar/remote_helper.py
@@ -397,7 +397,7 @@ def resolve_head(head):
                     heads = set(self._branchmap.heads()) & unknown_heads
                 getbundle(self._repo, self._store, heads,
                           self._branchmap.names())
-        except Exception:
+        except:
             wanted_refs = {}
             raise
         finally:
diff --git a/git-core b/git-core
index af6b65d45..b3d7a52fa 160000
--- a/git-core
+++ b/git-core
@@ -1 +1 @@
-Subproject commit af6b65d45ef179ed52087e80cb089f6b2349f4ec
+Subproject commit b3d7a52fac39193503a0b6728771d1bf6a161464
diff --git a/helper/GIT-VERSION.mk b/helper/GIT-VERSION.mk
index c6ac2d81d..1593a6ee3 100644
--- a/helper/GIT-VERSION.mk
+++ b/helper/GIT-VERSION.mk
@@ -1,2 +1,2 @@
-GIT_VERSION ?= v2.26.2
+GIT_VERSION ?= v2.27.0
 WINDOWS_GIT_VERSION ?= $(GIT_VERSION).windows.1
diff --git a/helper/cinnabar-fast-import.c b/helper/cinnabar-fast-import.c
index 8fb431b37..c289c5a81 100644
--- a/helper/cinnabar-fast-import.c
+++ b/helper/cinnabar-fast-import.c
@@ -9,7 +9,7 @@ static void start_packfile();
 #include "hg-bundle.h"
 #include "hg-data.h"
 #include "list.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 #include "strslice.h"
 #include "tree-walk.h"
 
@@ -131,6 +131,8 @@ static void init()
 	avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
 	marks = mem_pool_calloc(&fi_mem_pool, 1, sizeof(struct mark_set));
 
+	hashmap_init(&object_table, object_entry_hashcmp, NULL, 0);
+
 	global_argc = 1;
 
 	rc_free = mem_pool_alloc(&fi_mem_pool, cmd_save * sizeof(*rc_free));
@@ -266,7 +268,7 @@ static uintmax_t parse_mark_ref(const char *p, char **endptr)
 		e->pack_id = MAX_PACK_ID;
 		e->idx.offset = 1;
 	}
-	insert_mark(2, e);
+	insert_mark(marks, 2, e);
 	return 2;
 }
 
@@ -462,7 +464,7 @@ static void do_set(struct string_list *args)
 
 	if (args->items[2].string[0] == ':') {
 		uintmax_t mark = parse_mark_ref_eol(args->items[2].string);
-		struct object_entry *oe = find_mark(mark);
+		struct object_entry *oe = find_mark(marks, mark);
 		oidcpy(&git_id, &oe->idx.oid);
 	} else if (get_oid_hex(args->items[2].string, &git_id))
 		die("Invalid sha1");
diff --git a/helper/hg-connect.h b/helper/hg-connect.h
index 7eb69c21e..8776ddac5 100644
--- a/helper/hg-connect.h
+++ b/helper/hg-connect.h
@@ -2,7 +2,7 @@
 #define HG_CONNECT_H
 
 #include "run-command.h"
-#include "sha1-array.h"
+#include "oid-array.h"
 
 struct hg_connection_stdio {
 	FILE *out;