Many Examples Will Not Compile for the ESP8266

[aramperez]

Platform

ESP8266

IDE / Tooling

Arduino (IDE/CLI)

What happened?

I'm using Arduino IDE, Version: 2.3.5, Date: 2025-04-02T13:16:49.885Z, CLI Version: 1.2.0 with a NodeMCU ESP8266 and ESP Async WebServer, version 3.7.7.

I'm trying to compile the WebSocket example I get the following error:

`FQBN: esp8266:esp8266:nodemcuv2
Using board 'nodemcuv2' from platform in folder: C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2
Using core 'esp8266' from platform in folder: C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2

Detecting libraries used...

<--- snip -->

Compiling sketch...
"C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\tools\python3\3.7.2-post1/python3" -I "C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/signing.py" --mode header --publickey "C:\Users\aramp\AppData\Local\Temp\.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket/public.key" --out "C:\Users\aramp\AppData\Local\arduino\sketches\D3B0F7D0C4C9868042F85F60273FB0C6/core/Updater_Signing.h"
"C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\3.0.4-gcc10.3-1757bed/bin/xtensa-lx106-elf-g++" -D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ -D_GNU_SOURCE "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/include" "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include" "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/libc/xtensa-lx106-elf/include" "-IC:\Users\aramp\AppData\Local\arduino\sketches\D3B0F7D0C4C9868042F85F60273FB0C6/core" -c -Werror=return-type -Os -g -free -fipa-pta -mlongcalls -mtext-section-literals -fno-rtti -falign-functions=4 -std=gnu++17 -MMD -ffunction-sections -fdata-sections -fno-exceptions -DMMU_IRAM_SIZE=0x8000 -DMMU_ICACHE_SIZE=0x8000 -DNONOSDK22x_190703=1 -DF_CPU=80000000L -DLWIP_OPEN_SRC -DTCP_MSS=536 -DLWIP_FEATURES=1 -DLWIP_IPV6=0 -DARDUINO=10607 -DARDUINO_ESP8266_NODEMCU_ESP12E -DARDUINO_ARCH_ESP8266 "-DARDUINO_BOARD="ESP8266_NODEMCU_ESP12E"" -DLED_BUILTIN=2 -DFLASHMODE_DIO -DESP8266 "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266" "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\variants\nodemcu" "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src" "-Ic:\Users\aramp\Documents\Arduino\libraries\ESPAsyncTCP\src" "-Ic:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src" "-IC:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\Hash\src" "C:\Users\aramp\AppData\Local\arduino\sketches\D3B0F7D0C4C9868042F85F60273FB0C6\sketch\WebSocket.ino.cpp" -o "C:\Users\aramp\AppData\Local\arduino\sketches\D3B0F7D0C4C9868042F85F60273FB0C6\sketch\WebSocket.ino.cpp.o"
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:57:17: error: 'CLOSED' conflicts with a previous declaration
57 | CLOSED = 0,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:74:3: note: previous declaration 'wl_tcp_state CLOSED'
74 | CLOSED = 0,
| ^~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:58:17: error: 'LISTEN' conflicts with a previous declaration
58 | LISTEN = 1,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:75:3: note: previous declaration 'wl_tcp_state LISTEN'
75 | LISTEN = 1,
| ^~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:59:17: error: 'SYN_SENT' conflicts with a previous declaration
59 | SYN_SENT = 2,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:76:3: note: previous declaration 'wl_tcp_state SYN_SENT'
76 | SYN_SENT = 2,
| ^~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:60:17: error: 'SYN_RCVD' conflicts with a previous declaration
60 | SYN_RCVD = 3,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:77:3: note: previous declaration 'wl_tcp_state SYN_RCVD'
77 | SYN_RCVD = 3,
| ^~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:61:17: error: 'ESTABLISHED' conflicts with a previous declaration
61 | ESTABLISHED = 4,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:78:3: note: previous declaration 'wl_tcp_state ESTABLISHED'
78 | ESTABLISHED = 4,
| ^~~~~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:62:17: error: 'FIN_WAIT_1' conflicts with a previous declaration
62 | FIN_WAIT_1 = 5,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:79:3: note: previous declaration 'wl_tcp_state FIN_WAIT_1'
79 | FIN_WAIT_1 = 5,
| ^~~~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:63:17: error: 'FIN_WAIT_2' conflicts with a previous declaration
63 | FIN_WAIT_2 = 6,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:80:3: note: previous declaration 'wl_tcp_state FIN_WAIT_2'
80 | FIN_WAIT_2 = 6,
| ^~~~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:64:17: error: 'CLOSE_WAIT' conflicts with a previous declaration
64 | CLOSE_WAIT = 7,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:81:3: note: previous declaration 'wl_tcp_state CLOSE_WAIT'
81 | CLOSE_WAIT = 7,
| ^~~~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:65:17: error: 'CLOSING' conflicts with a previous declaration
65 | CLOSING = 8,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:82:3: note: previous declaration 'wl_tcp_state CLOSING'
82 | CLOSING = 8,
| ^~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:66:17: error: 'LAST_ACK' conflicts with a previous declaration
66 | LAST_ACK = 9,
| ^
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:83:3: note: previous declaration 'wl_tcp_state LAST_ACK'
83 | LAST_ACK = 9,
| ^~~~~~~~
In file included from c:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer\src/ESPAsyncWebServer.h:9,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:20:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2/tools/sdk/lwip2/include/lwip/tcpbase.h:67:17: error: 'TIME_WAIT' conflicts with a previous declaration
67 | TIME_WAIT = 10
| ^~
In file included from C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi\src/ESP8266WiFi.h:28,
from C:\Users\aramp\AppData\Local\Temp.arduinoIDE-unsaved2025411-2300-1027oqz.tra3\WebSocket\WebSocket.ino:13:
C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266/wl_definitions.h:84:3: note: previous declaration 'wl_tcp_state TIME_WAIT'
84 | TIME_WAIT = 10
| ^~~~~~~~~
Using library ESP8266WiFi at version 1.0 in folder: C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\ESP8266WiFi
Using library ESPAsyncTCP at version 1.2.4 in folder: C:\Users\aramp\Documents\Arduino\libraries\ESPAsyncTCP
Using library ESP Async WebServer at version 3.7.7 in folder: C:\Users\aramp\Documents\Arduino\libraries\ESP_Async_WebServer
Using library Hash at version 1.0 in folder: C:\Users\aramp\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\libraries\Hash
exit status 1

Compilation error: exit status 1`

I can compile the program by removing or commenting out lines 9 - 18 (it appears that similar lines are already in ESPAsyncWebServer.h, lines 18 - 31).

Stack Trace

Not applicable.

Minimal Reproductible Example (MRE)

Open up the WebSockets example.

I confirm that:

• I have read the documentation.
• I have searched for similar discussions.
• I have searched for similar issues.
• I have looked at the examples.
• I have upgraded to the lasted version of ESPAsyncWebServer (and AsyncTCP for ESP32).

[mathieucarbou]

Oh yes it pass! Look at the CI: https://github.com/ESP32Async/ESPAsyncWebServer/actions/runs/14935800791

[aramperez]

It appears that that test is on a Linux machine. I'm on a Windows 11 machine. I've tried several other examples with the same result.

[mathieucarbou]

It appears that that test is on a Linux machine. I'm on a Windows 11 machine. I've tried several other examples with the same result.

That's not an issue with the project.

Try go to your Arduino IDE lib folder, remove everything and restart downloading libs from scratch.
This IDE is terrible.
Either do not use it, or please make sure you know it deeply to the core and are able to solve all the issues it creates.
Make sure you download the right ones also.

Or switch to a real dev env like vscoce Vscode + pioarduino extension!

[aramperez]

I'm sorry you feel you have to treat me like I'm a nobody because I use Arduino IDE (or Linux). I don't know what vscoce or pioarduino extension is. I like to use Microsoft's Visual Studio Code with PlatformIO (VSC-PIO). But for a quick test, the Arduino IDE is much faster. If you don't want this library to be used with the IDE, then why support it?

I did remove all the libraries from the IDE using the IDE Library manager. But I will try to remove the files from the Windows file manager and re-install them to see if it makes a difference.

And with VSC-PIO, I have a different set of issues but I'll post those later.

[aramperez]

I removed both ESPAsync libraries using the Windows file manager and when I tried to compiled with the Arduino IDE, I received an error about ESPAsyncWebServer.h not being found. I installed both ESPAsyncWebServer and ESPAsyncTCP via the IDE and tried to recompile again. I still get the same errors I reported. I can only compile by commenting out the lines mentioned above.

[mathieucarbou]

PlatformIO dropped Arduino support.
For 3.x and more, you need to use pioarduino.

Are you able to reproduce the same issue by using PIO ?

• comment out line 22: src_dir = examples/PerfTests
• uncomment line 36: ; src_dir = examples/WebSocket

run: pio run -e esp8266

[aramperez]

I'm sorry to make you mad because I'm new at using this library. I had developed some some code last year using PlatformIO and the "standard" <ESP8266WebServer.h> and <WebSocketsServer.h> libraries without any issues. In the last few weeks I was able to add some new features and I never received any indication that PlatformIO had dropped Arduino support. Having seen several videos on ESPAsysncWebserver I started to convert to using it when I ran into some issues. That's when I went to the Arduino IDE to try the examples.

I erased my WebSockets example project, installed pioarduino into Visual Code Studio and created a new project. I added the lines from here to the platformio.ini file. I don't what file contain the lines 22 and 36 you mention above. However, I was able to successfully compile the example WebSockets. Thank you for your help.