diff --git a/.gitignore b/.gitignore
index 7a510743f..e1924aeb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,6 +15,8 @@
 # build artifacts
 mergerfs
 obj/
+*.d
+build/
 src/version.hpp
 
 # Debian files
@@ -23,3 +25,7 @@ debian/changelog
 
 # RPM files
 rpmbuild/
+
+# IDEs
+\.idea/
+VERSION
diff --git a/Makefile b/Makefile
index cd614eecc..bc4327cb0 100644
--- a/Makefile
+++ b/Makefile
@@ -93,6 +93,10 @@ LDFLAGS := \
     -pthread \
     -lrt
 
+ifeq ($(DEBUG),1)
+LDFLAGS := ${LDFLAGS} -fsanitize=undefined
+endif
+
 DESTDIR       =
 PREFIX        = /usr/local
 EXEC_PREFIX   = $(PREFIX)
diff --git a/src/branches.cpp b/src/branches.cpp
index 99a0eaf88..d5a57e3df 100644
--- a/src/branches.cpp
+++ b/src/branches.cpp
@@ -80,11 +80,8 @@ namespace l
     uint64_t offset;
 
     offset = s_.find_first_not_of("+<>-=");
-    if(offset > 1)
-      offset = 2;
+    *values_ = ((offset != std::string::npos) ? s_.substr(offset) : "");
     *instr_ = s_.substr(0,offset);
-    if(offset != std::string::npos)
-      *values_ = s_.substr(offset);
   }
 
   static
@@ -205,6 +202,9 @@ namespace l
     Branches::Impl tmp_branches(branches_->minfreespace());
 
     str::split(str_,':',&paths);
+    if (paths.empty())
+      return -ENOTSUP;
+
     for(auto &path : paths)
       {
         rv = l::parse(path,&tmp_branches);
@@ -269,6 +269,9 @@ namespace l
   int
   erase_begin(Branches::Impl *branches_)
   {
+    if (branches_->size() <= 1)
+      return -ENOTSUP;
+
     branches_->erase(branches_->begin());
 
     return 0;
@@ -278,6 +281,9 @@ namespace l
   int
   erase_end(Branches::Impl *branches_)
   {
+    if (branches_->size() <= 1)
+      return -ENOTSUP;
+
     branches_->pop_back();
 
     return 0;
@@ -299,6 +305,8 @@ namespace l
           {
             match = ::fnmatch(pi->c_str(),i->path.c_str(),0);
           }
+        if (match == 0 && branches_->size() == 1)
+          return -ENOTSUP;
 
         i = ((match == 0) ? branches_->erase(i) : (i+1));
       }
diff --git a/tests/tests.cpp b/tests/tests.cpp
index 3c9716762..1a667f553 100644
--- a/tests/tests.cpp
+++ b/tests/tests.cpp
@@ -115,6 +115,67 @@ test_config_branches()
   TEST_CHECK(b.from_string("./foo/bar:/bar/baz:blah/asdf") == 0);
 }
 
+
+void
+test_config_update_branches()
+{
+  uint64_t minfreespace;
+  Branches b(minfreespace);
+
+  minfreespace = 1234;
+
+  //
+  TEST_CHECK(b.from_string("/first:/second") == 0);
+
+  TEST_CHECK(b.from_string("-/first") == 0);
+  TEST_CHECK(b.to_string() == "/second=RW");
+
+  TEST_CHECK(b.from_string("+>/last") == 0);
+  TEST_CHECK(b.to_string() == "/second=RW:/last=RW");
+
+  TEST_CHECK(b.from_string("+/last") == 0);
+  TEST_CHECK(b.to_string() == "/second=RW:/last=RW:/last=RW");
+
+  //
+  TEST_CHECK(b.from_string("/second") == 0);
+
+  TEST_CHECK(b.from_string("+</first") == 0);
+  TEST_CHECK(b.to_string() == "/first=RW:/second=RW");
+
+  //
+  TEST_CHECK(b.from_string("/first:/second") == 0);
+  TEST_CHECK(b.from_string("-/second") == 0);
+  TEST_CHECK(b.to_string() == "/first=RW");
+
+  //
+  TEST_CHECK(b.from_string("/first:/second") == 0);
+
+  TEST_CHECK(b.from_string("->") == 0);
+  TEST_CHECK(b.to_string() == "/first=RW");
+
+  //
+  TEST_CHECK(b.from_string("/first:/second") == 0);
+
+  TEST_CHECK(b.from_string("-<") == 0);
+  TEST_CHECK(b.to_string() == "/second=RW");
+
+  //
+  TEST_CHECK(b.from_string("=/dir") == 0);
+  TEST_CHECK(b.to_string() == "/dir=RW");
+  TEST_CHECK(b.from_string("/dir") == 0);
+  TEST_CHECK(b.to_string() == "/dir=RW");
+
+  // error out when no branches left
+  TEST_CHECK(b.from_string("=/dir") == 0);
+  TEST_CHECK(b.from_string("-/dir") < 0);
+  TEST_CHECK(b.from_string("-<") < 0);
+  TEST_CHECK(b.from_string("->") < 0);
+
+  // error out when setting empty branches
+  TEST_CHECK(b.from_string("=") < 0);
+  TEST_CHECK(b.from_string("") < 0);
+}
+
 void
 test_config_cachefiles()
 {
@@ -274,6 +335,7 @@ TEST_LIST =
    {"config_int",test_config_int},
    {"config_str",test_config_str},
    {"config_branches",test_config_branches},
+   {"config_update_branches",test_config_update_branches},
    {"config_cachefiles",test_config_cachefiles},
    {"config_inodecalc",test_config_inodecalc},
    {"config_moveonenospc",test_config_moveonenospc},
diff --git a/tools/git2debcl b/tools/git2debcl
index 8d0423ce8..69ed69c8b 100755
--- a/tools/git2debcl
+++ b/tools/git2debcl
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
 
@@ -19,7 +19,7 @@ import subprocess
 import argparse
 
 def call(args):
-    return subprocess.Popen(args,stdout=subprocess.PIPE).communicate()[0].decode()
+    return subprocess.Popen(args,stdout=subprocess.PIPE).communicate()[0].decode('utf-8')
 
 def git_tags():
     args = ["git", "tag", '-l']