diff --git a/docs/check_doc_warnings.sh b/docs/check_doc_warnings.sh
index 87bf6b397..4d22b2903 100755
--- a/docs/check_doc_warnings.sh
+++ b/docs/check_doc_warnings.sh
@@ -18,8 +18,7 @@ fi
 # the Sphinx warning log
 # (escape char removal from https://www.commandlinefu.com/commands/view/6141/remove-color-codes-special-characters-with-sed
 sed -r 's:\x1B\[[0-9;]*[mK]::g' sphinx-warning-log.txt | \
-    sed -E "s~${IDF_PATH}~\${IDF_PATH}~" | \
-    sed -E "s/:[0-9]+:/:line:/" > sphinx-warning-log-sanitized.txt
+    sed -E "s/.*\/(.*):[0-9]+:/\1:line:/" > sphinx-warning-log-sanitized.txt
 
 # diff sanitized warnings, ignoring lines which only appear in ../sphinx-known-warnings.txt
 
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 6a4de8f3f..c495384ea 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,12 +1,12 @@
 # This is a list of python packages used to generate documentation. This file is used with pip:
 # pip install --user -r requirements.txt
 #
-sphinx==1.6.5
+sphinx>=1.6.5
 sphinx-rtd-theme
-breathe==4.7.3
-sphinxcontrib-blockdiag==1.5.3
-sphinxcontrib-seqdiag==0.8.5
-sphinxcontrib-actdiag==0.8.5
-sphinxcontrib-nwdiag==0.9.5
+breathe>=4.7.3
+sphinxcontrib-blockdiag>=1.5.3
+sphinxcontrib-seqdiag>=0.8.5
+sphinxcontrib-actdiag>=0.8.5
+sphinxcontrib-nwdiag>=0.9.5
 recommonmark
 future>=0.16.0 # for ../tools/gen_esp_err_to_name.py
diff --git a/docs/sphinx-known-warnings.txt b/docs/sphinx-known-warnings.txt
index 2dcc2368a..72fb40a5b 100644
--- a/docs/sphinx-known-warnings.txt
+++ b/docs/sphinx-known-warnings.txt
@@ -2,7 +2,7 @@
 #
 # Build will fail if sphinx-warning-log.txt contains any lines
 # which are not in this file. Lines are pre-sanitized by
-# check_doc_warnings.sh to remove formatting, paths, line numbers.
+# check_doc_warnings.sh to remove formatting, paths and line numbers.
 #
 # Warnings in this file must be in the same overall order as the log file.
 #
@@ -10,9 +10,74 @@
 #
 # Sphinx known issue https://github.com/sphinx-doc/sphinx/issues/2683
 #
-_build/inc/esp_a2dp_api.inc:line: WARNING: Invalid definition: Expected identifier in nested name. [error at 21]
+# Note: warnings below will be gone after upgrade
+#       to the following package==version
+#
+#       sphinx==1.8.4
+#       breathe==4.11.1
+#
+esp_a2dp_api.inc:line: WARNING: Invalid definition: Expected identifier in nested name. [error at 21]
   union esp_a2d_mcc_t::@1  esp_a2d_mcc_t::cie
   ---------------------^
-_build/inc/esp_bt_defs.inc:line: WARNING: Invalid definition: Expected identifier in nested name. [error at 21]
+esp_bt_defs.inc:line: WARNING: Invalid definition: Expected identifier in nested name. [error at 21]
   union esp_bt_uuid_t::@0  esp_bt_uuid_t::uuid
   ---------------------^
+
+#
+# Breathe known issue: https://github.com/michaeljones/breathe/issues/405
+# Sphinx known issue: https://github.com/sphinx-doc/sphinx/pull/5901
+#
+# Note: warnings below have been identified after upgrade
+#       to the following package==version
+#
+#       sphinx==1.8.4
+#       breathe==4.11.1
+#
+ulp-cmake.rst:line: WARNING: Duplicate declaration, esp_err_t ulp_load_binary(uint32_t load_addr, const uint8_t * program_binary, size_t program_size)
+ulp-cmake.rst:line: WARNING: Duplicate declaration, esp_err_t ulp_run(uint32_t entry_point)
+ulp-cmake.rst:line: WARNING: Duplicate declaration, esp_err_t ulp_set_wakeup_period(size_t period_index, uint32_t period_us)
+README.rst:line: WARNING: Duplicate declaration, esp_err_t ulp_run(uint32_t entry_point)
+#
+# Issue present only when building on msys2 / mingw32 START >>>
+#
+esp_spp_api.inc:line: WARNING: Error in type declaration.
+If typedef-like declaration:
+  Type must be either just a name or a typedef-like declaration.
+  If just a name:
+    Error in declarator or parameters and qualifiers
+    Invalid definition: Expected identifier in nested name, got keyword: void [error at 4]
+      void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+      ----^
+  If typedef-like declaration:
+    Error in declarator
+    If pointer to member declarator:
+      Invalid definition: Expected identifier in nested name. [error at 4]
+        void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+        ----^
+    If declId, parameters, and qualifiers:
+      Invalid definition: Expected identifier in nested name. [error at 4]
+        void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+        ----^
+    If parenthesis in noptr-declarator:
+      Error in declarator or parameters and qualifiers
+      If pointer to member declarator:
+        Invalid definition: Expected identifier in nested name. [error at 5]
+          void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+          -----^
+      If declarator-id:
+        Invalid definition: Expected identifier in nested name. [error at 5]
+          void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+          -----^
+If type alias or template alias:
+  Invalid definition: Expected identifier in nested name, got keyword: void [error at 4]
+    void() esp_spp_cb_t(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)
+    ----^
+#
+# Issue present only when building on msys2 / mingw32 END <<<
+#
+spi_master.inc:line: WARNING: Duplicate declaration, struct spi_transaction_t spi_transaction_t
+spi_slave.inc:line: WARNING: Duplicate declaration, struct spi_slave_transaction_t spi_slave_transaction_t
+wear-levelling.rst:line: WARNING: Duplicate declaration, bool esp_vfs_fat_mount_config_t::format_if_mount_failed
+wear-levelling.rst:line: WARNING: Duplicate declaration, int esp_vfs_fat_mount_config_t::max_files
+wear-levelling.rst:line: WARNING: Duplicate declaration, size_t esp_vfs_fat_mount_config_t::allocation_unit_size
+wear-levelling.rst:line: WARNING: Duplicate declaration, esp_vfs_fat_mount_config_t