diff --git a/.gdbinit b/.gdbinit
index 6a43ac3fe00..2259ac16e39 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -13,3 +13,6 @@ source buildscripts/gdb/mongo_lock.py
 
 # Load methods for printing in-memory contents of WT tables.
 source buildscripts/gdb/wt_dump_table.py
+
+# Load third-party pretty printers
+source src/third_party/immer/dist/tools/gdb_pretty_printers/autoload.py
diff --git a/buildscripts/gdb/mongo_printers.py b/buildscripts/gdb/mongo_printers.py
index 0a85a2655ae..95780dd50dc 100644
--- a/buildscripts/gdb/mongo_printers.py
+++ b/buildscripts/gdb/mongo_printers.py
@@ -9,8 +9,12 @@ from pathlib import Path
 import gdb
 import gdb.printing
 
+ROOT_PATH = str(Path(os.path.abspath(__file__)).parent.parent.parent)
+if ROOT_PATH not in sys.path:
+    sys.path.insert(0, ROOT_PATH)
+from src.third_party.immer.dist.tools.gdb_pretty_printers.printers import ListIter as ImmerListIter  # pylint: disable=wrong-import-position
+
 if not gdb:
-    sys.path.insert(0, str(Path(os.path.abspath(__file__)).parent.parent.parent))
     from buildscripts.gdb.mongo import get_boost_optional
     from buildscripts.gdb.optimizer_printers import register_abt_printers
 
@@ -600,6 +604,61 @@ class AbslFlatHashMapPrinter(AbslHashMapPrinterBase):
             yield ('value', kvp['value'])
 
 
+class ImmutableMapIter(ImmerListIter):
+    def __init__(self, val):
+        super().__init__(val)
+        self.max = (1 << 64) - 1
+        self.pair = None
+        self.curr = (None, self.max, self.max)
+
+    def __next__(self):
+        if self.pair:
+            result = ('value', self.pair['second'])
+            self.pair = None
+            self.i += 1
+            return result
+        if self.i == self.size:
+            raise StopIteration
+        if self.i < self.curr[1] or self.i >= self.curr[2]:
+            self.curr = self.region()
+        self.pair = self.curr[0][self.i - self.curr[1]].cast(
+            gdb.lookup_type(self.v.type.template_argument(0).name))
+        result = ('key', self.pair['first'])
+        return result
+
+
+class ImmutableMapPrinter:
+    """Pretty-printer for mongo::immutable::map<>."""
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return '%s of size %d' % (self.val.type, int(self.val['_storage']['impl_']['size']))
+
+    def children(self):
+        return ImmutableMapIter(self.val['_storage'])
+
+    def display_hint(self):
+        return 'map'
+
+
+class ImmutableSetPrinter:
+    """Pretty-printer for mongo::immutable::set<>."""
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return '%s of size %d' % (self.val.type, int(self.val['_storage']['impl_']['size']))
+
+    def children(self):
+        return ImmerListIter(self.val['_storage'])
+
+    def display_hint(self):
+        return 'array'
+
+
 def find_match_brackets(search, opening='<', closing='>'):
     """Return the index of the closing bracket that matches the first opening bracket.
 
@@ -925,6 +984,8 @@ def build_pretty_printer():
     pp.add('__wt_update', '__wt_update', False, WtUpdateToBsonPrinter)
     pp.add('CodeFragment', 'mongo::sbe::vm::CodeFragment', False, SbeCodeFragmentPrinter)
     pp.add('boost::optional', 'boost::optional', True, BoostOptionalPrinter)
+    pp.add('immutable::map', 'mongo::immutable::map', True, ImmutableMapPrinter)
+    pp.add('immutable::set', 'mongo::immutable::set', True, ImmutableSetPrinter)
 
     # Optimizer/ABT related pretty printers that can be used only with a running process.
     register_abt_printers(pp)
diff --git a/src/third_party/immer/dist/README.rst b/src/third_party/immer/dist/README.rst
index abf4dceae14..195065209ad 100644
--- a/src/third_party/immer/dist/README.rst
+++ b/src/third_party/immer/dist/README.rst
@@ -1,6 +1,6 @@
 .. image:: https://github.com/arximboldi/immer/workflows/test/badge.svg
    :target: https://github.com/arximboldi/immer/actions?query=workflow%3Atest+branch%3Amaster
-   :alt: Github Actions Badge
+   :alt: GitHub Actions Badge
 
 .. image:: https://codecov.io/gh/arximboldi/immer/branch/master/graph/badge.svg
    :target: https://codecov.io/gh/arximboldi/immer
@@ -74,7 +74,7 @@ Example
   For a **complete example** check `Ewig, a simple didactic
   text-editor <https://github.com/arximboldi/ewig>`_ built with this
   library.  You may also wanna check `Lager, a Redux-like library
-  <https://github.com/arximboldi/lager>`_ for writting interactive
+  <https://github.com/arximboldi/lager>`_ for writing interactive
   software in C++ using a value-oriented design.
 
 
diff --git a/src/third_party/immer/dist/tools/gdb_pretty_printers/__init__.py b/src/third_party/immer/dist/tools/gdb_pretty_printers/__init__.py
new file mode 100644
index 00000000000..1bb8bf6d7fd
--- /dev/null
+++ b/src/third_party/immer/dist/tools/gdb_pretty_printers/__init__.py
@@ -0,0 +1 @@
+# empty
diff --git a/src/third_party/immer/dist/tools/gdb_pretty_printers/autoload.py b/src/third_party/immer/dist/tools/gdb_pretty_printers/autoload.py
new file mode 100644
index 00000000000..727a777772e
--- /dev/null
+++ b/src/third_party/immer/dist/tools/gdb_pretty_printers/autoload.py
@@ -0,0 +1,11 @@
+import gdb.printing
+import os
+
+path = os.path.dirname(__file__)
+if not path in sys.path:
+    sys.path.append(path)
+from printers import immer_lookup_function
+
+gdb.printing.register_pretty_printer(gdb.current_objfile(), immer_lookup_function)
+
+print("immer gdb pretty-printers loaded")
\ No newline at end of file
diff --git a/src/third_party/immer/dist/tools/gdb_pretty_printers/printers.py b/src/third_party/immer/dist/tools/gdb_pretty_printers/printers.py
new file mode 100644
index 00000000000..c33e7efdf67
--- /dev/null
+++ b/src/third_party/immer/dist/tools/gdb_pretty_printers/printers.py
@@ -0,0 +1,485 @@
+# Sourced from https://gist.github.com/dwightguth/283afe96b60b3793f3c02036701457f8
+# with light modifications.
+
+import gdb.printing
+import decimal
+import traceback
+import re
+
+MAX = 1 << 64 - 1
+
+
+class ArrayIter:
+    def __init__(self, val):
+        self.val_ptr = val.type.template_argument(0).pointer()
+        self.v = val['impl_']
+        self.size = self.v['size']
+        self.i = 0
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.i == self.size:
+            raise StopIteration
+        ptr = self.v['ptr']
+        data = ptr.dereference()['impl']['d']['buffer'].address.reinterpret_cast(self.val_ptr)
+        result = ('[%d]' % self.i, data[self.i])
+        self.i += 1
+        return result
+
+
+class Relaxed:
+    def __init__(self, node, shift, relaxed, it):
+        self.node = node
+        self.shift = shift
+        self.relaxed = relaxed
+        self.it = it
+        self.B = self.node.type.target().template_argument(2)
+        self.BL = self.node.type.target().template_argument(3)
+
+    def index(self, idx):
+        offset = idx >> self.shift
+        while self.relaxed.dereference()['d']['sizes'][offset] <= idx:
+            offset += 1
+        return offset
+
+    def towards(self, idx):
+        offset = self.index(idx)
+        left_size = self.relaxed.dereference()['d']['sizes'][offset - 1] if offset else 0
+        child = self.it.inner(self.node)[offset]
+        is_leaf = self.shift == self.BL
+        next_size = self.relaxed.dereference()['d']['sizes'][offset] - left_size
+        next_idx = idx - left_size
+        if is_leaf:
+            return self.it.visit_leaf(LeafSub(child, next_size), next_idx)
+        else:
+            return self.it.visit_maybe_relaxed_sub(child, self.shift - self.B, next_size, next_idx)
+
+
+class LeafSub:
+    def __init__(self, node, count):
+        self.node = node
+        self.count_ = count
+        self.BL = self.node.type.target().template_argument(3)
+        self.MASK = (1 << self.BL) - 1
+
+    def index(self, idx):
+        return idx & self.MASK
+
+    def count(self):
+        return self.count_
+
+
+class FullLeaf:
+    def __init__(self, node):
+        self.node = node
+        self.BL = self.node.type.target().template_argument(3)
+        self.BRANCHES = 1 << self.BL
+        self.MASK = self.BRANCHES - 1
+
+    def index(self, idx):
+        return idx & self.MASK
+
+    def count(self):
+        return self.BRANCHES
+
+
+class Leaf:
+    def __init__(self, node, size):
+        self.node = node
+        self.size = size
+        self.BL = self.node.type.target().template_argument(3)
+        self.MASK = (1 << self.BL) - 1
+
+    def index(self, idx):
+        return idx & self.MASK
+
+    def count(self):
+        return self.index(self.size - 1) + 1
+
+
+class RegularSub:
+    def __init__(self, node, shift, size, it):
+        self.node = node
+        self.shift = shift
+        self.size = size
+        self.it = it
+        self.B = self.node.type.target().template_argument(2)
+        self.MASK = (1 << self.B) - 1
+
+    def towards(self, idx):
+        offset = self.index(idx)
+        count = self.count()
+        return self.it.towards_regular(self, idx, offset, count)
+
+    def index(self, idx):
+        return (idx >> self.shift) & self.MASK
+
+    def count(self):
+        return self.subindex(self.size - 1) + 1
+
+    def subindex(self, idx):
+        return idx >> self.shift
+
+
+class Regular:
+    def __init__(self, node, shift, size, it):
+        self.node = node
+        self.shift = shift
+        self.size = size
+        self.it = it
+        self.B = self.node.type.target().template_argument(2)
+        self.MASK = (1 << self.B) - 1
+
+    def index(self, idx):
+        return (idx >> self.shift) & self.MASK
+
+    def count(self):
+        return self.index(self.size - 1) + 1
+
+    def towards(self, idx):
+        offset = self.index(idx)
+        count = self.count()
+        return self.it.towards_regular(self, idx, offset, count)
+
+
+class Full:
+    def __init__(self, node, shift, it):
+        self.node = node
+        self.shift = shift
+        self.it = it
+        self.B = self.node.type.target().template_argument(2)
+        self.BL = self.node.type.target().template_argument(3)
+        self.MASK = (1 << self.B) - 1
+
+    def index(self, idx):
+        return (idx >> self.shift) & self.MASK
+
+    def towards(self, idx):
+        offset = self.index(idx)
+        is_leaf = self.shift == self.BL
+        child = self.it.inner(self.node)[offset]
+        if is_leaf:
+            return self.it.visit_leaf(FullLeaf(child), idx)
+        else:
+            return Full(child, self.shift - self.B, self.it).towards(idx)
+
+
+class ListIter:
+    def __init__(self, val):
+        self.v = val['impl_']
+        self.size = self.v['size']
+        self.i = 0
+        self.curr = (None, MAX, MAX)
+        self.node_ptr_ptr = self.v['root'].type.pointer()
+        self.B = self.v['root'].type.target().template_argument(2)
+        self.BL = self.v['root'].type.target().template_argument(3)
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.i == self.size:
+            raise StopIteration
+        if self.i < self.curr[1] or self.i >= self.curr[2]:
+            self.curr = self.region()
+        result = ('[%d]' % self.i, self.curr[0][self.i - self.curr[1]].cast(
+            gdb.lookup_type(self.v.type.template_argument(0).name)))
+        self.i += 1
+        return result
+
+    def region(self):
+        tail_off = self.tail_offset()
+        if self.i >= tail_off:
+            return (self.leaf(self.v['tail']), tail_off, self.size)
+        else:
+            subs = self.visit_maybe_relaxed_sub(self.v['root'], self.v['shift'], tail_off, self.i)
+            first = self.i - subs[1]
+            end = first + subs[2]
+            return (subs[0], first, end)
+
+    def tail_offset(self):
+        r = self.relaxed(self.v['root'])
+        if r:
+            return r.dereference()['d']['sizes'][r.dereference()['d']['count'] - 1]
+        elif self.size:
+            return (self.size - 1) & ~self.leaf_mask()
+        else:
+            return 0
+
+    def relaxed(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['relaxed']
+
+    def leaf(self, node):
+        return node.dereference()['impl']['d']['data']['leaf']['buffer'].address
+
+    def inner(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['buffer'].address.reinterpret_cast(
+            self.node_ptr_ptr)
+
+    def visit_maybe_relaxed_sub(self, node, shift, size, idx):
+        relaxed = self.relaxed(node)
+        if relaxed:
+            return Relaxed(node, shift, relaxed, self).towards(idx)
+        else:
+            return RegularSub(node, shift, size, self).towards(idx)
+
+    def visit_leaf(self, pos, idx):
+        return (self.leaf(pos.node), pos.index(idx), pos.count())
+
+    # pos = node, idx = full, offset = shifted & masked, count = shifted
+    def towards_regular(self, pos, idx, offset, count):
+        is_leaf = pos.shift == self.BL
+        child = self.inner(pos.node)[offset]
+        is_full = offset + 1 != count
+        if is_full:
+            if is_leaf:
+                return self.visit_leaf(FullLeaf(child), idx)
+            else:
+                return Full(child, pos.shift - self.B, self).towards(idx)
+        elif is_leaf:
+            return self.visit_leaf(Leaf(child, pos.size), idx)
+        else:
+            return Regular(child, pos.shift - self.B, pos.size, self).towards(idx)
+
+    def leaf_mask(self):
+        return (1 << self.BL) - 1
+
+
+def popcount(x):
+    b = 0
+    while x > 0:
+        x &= x - 1
+        b += 1
+    return b
+
+
+class ChampIter:
+    def __init__(self, val):
+        self.depth = 0
+        self.count = 0
+        v = val['impl_']['root']
+        self.node_ptr_ptr = v.type.pointer()
+        m = self.datamap(v)
+        if m:
+            self.cur = self.values(v)
+            self.end = self.values(v) + popcount(m)
+        else:
+            self.cur = None
+            self.end = None
+        self.path = [v.address]
+        self.B = v.type.target().template_argument(4)
+        self.MAX_DEPTH = ((8 * 8) + self.B - 1) / 8
+        self.ensure_valid()
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        if self.cur == None:
+            raise StopIteration
+        result = self.cur.dereference()
+        self.cur += 1
+        self.count += 1
+        self.ensure_valid()
+        return result
+
+    def ensure_valid(self):
+        while self.cur == self.end:
+            while self.step_down():
+                if self.cur != self.end:
+                    return
+            if not self.step_right():
+                self.cur = None
+                self.end = None
+                return
+
+    def step_down(self):
+        if self.depth < self.MAX_DEPTH:
+            parent = self.path[self.depth].dereference()
+            if self.nodemap(parent):
+                self.depth += 1
+                self.path.append(self.children(parent))
+                child = self.path[self.depth]
+                if self.depth < self.MAX_DEPTH:
+                    m = self.datamap(child)
+                    if m:
+                        self.cur = self.values(child)
+                        self.end = self.cur + popcount(m)
+                else:
+                    self.cur = self.collisions(child)
+                    self.end = self.cur = self.collision_count(child)
+                return True
+        return False
+
+    def step_right(self):
+        while self.depth > 0:
+            parent = self.path[self.depth - 1].dereference()
+            last = self.children(parent) + popcount(self.nodemap(parent))
+            next_ = self.path[self.depth] + 1
+            if next_ < last:
+                self.path[self.depth] = next_
+                child = self.path[self.depth].dereference()
+                if self.depth < self.MAX_DEPTH:
+                    m = self.datamap(child)
+                    if m:
+                        self.cur = self.values(child)
+                        self.end = self.cur + popcount(m)
+                else:
+                    self.cur = self.collisions(child)
+                    self.end = self.cur + self.collision_count(child)
+                return True
+            self.depth -= 1
+            self.path.pop()
+        return False
+
+    def values(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['values'].dereference(
+        )['d']['buffer'].address.cast(self.T_ptr)
+
+    def children(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['buffer'].address.cast(
+            self.node_ptr_ptr)
+
+    def datamap(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['datamap']
+
+    def nodemap(self, node):
+        return node.dereference()['impl']['d']['data']['inner']['nodemap']
+
+    def collision_count(self, node):
+        return node.dereference()['impl']['d']['data']['collision']['count']
+
+    def collisions(self, node):
+        return node.dereference()['impl']['d']['data']['collision']['buffer'].address.cast(
+            self.T_ptr)
+
+
+class MapIter(ChampIter):
+    def __init__(self, val):
+        self.T_ptr = gdb.lookup_type("std::pair<" + val.type.template_argument(0).name + ", " +
+                                     val.type.template_argument(1).name + ">").pointer()
+        ChampIter.__init__(self, val)
+        self.pair = None
+
+    def __next__(self):
+        if self.pair:
+            result = ('[%d]' % self.count, self.pair['second'])
+            self.pair = None
+            return result
+        self.pair = super().__next__()
+        return ('[%d]' % self.count, self.pair['first'])
+
+
+class SetIter(ChampIter):
+    def __init__(self, val):
+        self.T_ptr = gdb.lookup_type(val.type.template_argument(0).name).pointer()
+        ChampIter.__init__(self, val)
+
+    def __next__(self):
+        return ('[%d]' % self.count, super().__next__())
+
+
+def num_elements(num):
+    return '1 element' if num == 1 else '%d elements' % num
+
+
+class ArrayPrinter:
+    "Prints an immer::array"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return 'immer::array with %s' % num_elements(self.val['impl_']['size'])
+
+    def children(self):
+        return ArrayIter(self.val)
+
+    def display_hint(self):
+        return 'array'
+
+
+class MapPrinter:
+    "Print an immer::map"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return 'immer::map with %s' % num_elements(self.val['impl_']['size'])
+
+    def children(self):
+        return MapIter(self.val)
+
+    def display_hint(self):
+        return 'map'
+
+
+class SetPrinter:
+    "Prints an immer::set"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return 'immer::set with %s' % num_elements(self.val['impl_']['size'])
+
+    def children(self):
+        return SetIter(self.val)
+
+
+class TablePrinter:
+    "Prints an immer::table"
+
+    def __init__(self, val):
+        self.val = val
+
+    def to_string(self):
+        return 'immer::table with %s' % num_elements(self.val['impl_']['size'])
+
+    def children(self):
+        return SetIter(self.val)
+
+
+class ListPrinter:
+    "Prints an immer::vector or immer::flex_vector"
+
+    def __init__(self, val, typename):
+        self.val = val
+        self.typename = typename
+
+    def to_string(self):
+        return '%s of length %d' % (self.typename, int(self.val['impl_']['size']))
+
+    def children(self):
+        return ListIter(self.val)
+
+    def display_hint(self):
+        return 'array'
+
+
+def immer_lookup_function(val):
+    compiled_rx = re.compile('^([a-zA-Z0-9_:]+)(<.*>)?$')
+    typename = gdb.types.get_basic_type(val.type).tag
+    if not typename:
+        return None
+    match = compiled_rx.match(typename)
+    if not match:
+        return None
+
+    basename = match.group(1)
+    if basename == "immer::array":
+        return ArrayPrinter(val)
+    elif basename == "immer::map":
+        return MapPrinter(val)
+    elif basename == "immer::set":
+        return SetPrinter(val)
+    elif basename == "immer::table":
+        return TablePrinter(val)
+    elif basename == "immer::vector":
+        return ListPrinter(val, "immer::vector")
+    elif basename == "immer::flex_vector":
+        return ListPrinter(val, "immer::flex_vector")
+    return None
diff --git a/src/third_party/immer/scripts/import.sh b/src/third_party/immer/scripts/import.sh
index 13bd7860daa..b157196fa6a 100755
--- a/src/third_party/immer/scripts/import.sh
+++ b/src/third_party/immer/scripts/import.sh
@@ -27,7 +27,13 @@ rm -rf $LIB_GIT_DIR/example
 rm -rf $LIB_GIT_DIR/extra
 rm -rf $LIB_GIT_DIR/nix
 rm -rf $LIB_GIT_DIR/test
-rm -rf $LIB_GIT_DIR/tools
+rm -rf $LIB_GIT_DIR/tools/clojure
+rm -rf $LIB_GIT_DIR/tools/docker
+rm -rf $LIB_GIT_DIR/tools/include
+rm -rf $LIB_GIT_DIR/tools/scala
+rm -rf $LIB_GIT_DIR/tools/sinusoidal-sphinx-theme
+rm -rf $LIB_GIT_DIR/tools/reproduce-paper-results.bash
+rm -rf $LIB_GIT_DIR/tools/with-tee.bash
 rm -f $LIB_GIT_DIR/BUILD
 rm -f $LIB_GIT_DIR/CMakeLists.txt
 rm -f $LIB_GIT_DIR/Package.swift