https://github.com/WayfireWM/wayfire/issues/1351

In file included from ../src/core/core.cpp:17:
../src/api/wayfire/nonstd/wlroots-full.hpp:85:10: fatal error: 'wlr/backend/noop.h' file not found
#include <wlr/backend/noop.h>
         ^~~~~~~~~~~~~~~~~~~~
../src/core/output-layout.cpp:630:25: error: no member named 'front_buffer' in 'wlr_output'
        if (wo->handle->front_buffer == NULL)
            ~~~~~~~~~~  ^
../src/core/output-layout.cpp:637:48: error: no member named 'front_buffer' in 'wlr_output'
        if (!wlr_buffer_get_dmabuf(wo->handle->front_buffer, &attributes))
                                   ~~~~~~~~~~  ^

--- plugins/single_plugins/preserve-output.cpp.orig	2021-06-23 13:11:20 UTC
+++ plugins/single_plugins/preserve-output.cpp
@@ -297,7 +297,7 @@ class wayfire_preserve_output : public wf::plugin_inte
   public:
     void init() override
     {
-        if (wlr_output_is_noop(output->handle))
+        if (wlr_output_is_headless(output->handle))
         {
             // Don't do anything for NO-OP outputs
             return;
--- src/api/wayfire/nonstd/wlroots-full.hpp.orig	2021-06-23 13:11:20 UTC
+++ src/api/wayfire/nonstd/wlroots-full.hpp
@@ -81,7 +81,7 @@ extern "C"
 #if WLR_HAS_X11_BACKEND
     #include <wlr/backend/x11.h>
 #endif
-#include <wlr/backend/noop.h>
+#include <wlr/backend/headless.h>
 #include <wlr/backend/wayland.h>
 #undef static
 #include <wlr/backend/libinput.h>
--- src/core/output-layout.cpp.orig	2021-06-23 13:11:20 UTC
+++ src/core/output-layout.cpp
@@ -439,7 +439,7 @@ struct output_layout_output_t
          * focused */
         wlr_output *focused = get_core().get_active_output() ?
             get_core().get_active_output()->handle : nullptr;
-        if (!focused || wlr_output_is_noop(focused))
+        if (!focused || wlr_output_is_headless(focused))
         {
             get_core().focus_output(wo);
         }
@@ -627,14 +627,14 @@ struct output_layout_output_t
         }
 
         wlr_dmabuf_attributes attributes;
-        if (wo->handle->front_buffer == NULL)
+        if (wo->handle->back_buffer == NULL)
         {
             LOGE("Got empty buffer on ", wo->handle->name);
 
             return;
         }
 
-        if (!wlr_buffer_get_dmabuf(wo->handle->front_buffer, &attributes))
+        if (!wlr_buffer_get_dmabuf(wo->handle->back_buffer, &attributes))
         {
             LOGE("Failed reading mirrored output contents from ", wo->handle->name);
 
@@ -653,7 +653,7 @@ struct output_layout_output_t
 
     void set_enabled(bool enabled)
     {
-        if (wlr_output_is_noop(handle))
+        if (wlr_output_is_headless(handle))
         {
             return;
         }
@@ -740,7 +740,7 @@ struct output_layout_output_t
      */
     void emit_configuration_changed(uint32_t changed_fields)
     {
-        if (!wlr_output_is_noop(handle) && changed_fields)
+        if (!wlr_output_is_headless(handle) && changed_fields)
         {
             wf::output_configuration_changed_signal data{current_state};
             data.output = output.get();
@@ -903,7 +903,7 @@ class output_layout_t::impl
         on_config_reload = [=] (void*) { reconfigure_from_config(); };
         get_core().connect_signal("reload-config", &on_config_reload);
 
-        noop_backend = wlr_noop_backend_create(get_core().display);
+        noop_backend = wlr_headless_backend_create(get_core().display);
         wlr_backend_start(noop_backend);
 
         get_core().connect_signal("_backend_started", &on_backend_started);
@@ -989,7 +989,7 @@ class output_layout_t::impl
 
         if (!noop_output)
         {
-            auto handle = wlr_noop_add_output(noop_backend);
+            auto handle = wlr_headless_add_output(noop_backend, 800, 600);
             noop_output = std::make_unique<output_layout_output_t>(handle);
         }
 
--- src/core/wm.cpp.orig	2021-06-23 13:11:20 UTC
+++ src/core/wm.cpp
@@ -48,7 +48,7 @@ void wayfire_exit::init()
         int cnt_other_outputs = 0;
         for (auto& wo : wf::get_core().output_layout->get_outputs())
         {
-            if ((wo != output) && !wlr_output_is_noop(wo->handle))
+            if ((wo != output) && !wlr_output_is_headless(wo->handle))
             {
                 ++cnt_other_outputs;
             }
--- src/output/render-manager.cpp	2021-06-23 13:11:20 UTC
+++ src/output/render-manager.cpp
@@ -691,7 +691,7 @@ class wf::render_manager::impl
 
         on_frame.set_callback([&] (void*)
         {
-            if (wlr_output_is_noop(output->handle))
+            if (wlr_output_is_headless(output->handle))
             {
                 return;
             }