Stange compile issues

[Macrosii]

Hi I am encountering some strange compile issues.

Raspbery PI 5 8GB
Bookworm 64bit
IDE 1.8.19
V 3.8.11
I have been using the library for months and v3.8.1 since release.
I just tried the vanilla Multicore example and get the following compile error , but it compiles ok with the "Pico SDK stack" ??
Strange that previous code I was working on (see below) with "Serial" compiles ok with the TinyUSB stack.

Arduino: 1.8.19 (Linux), TD: 1.59, Board: "Raspberry Pi Pico, 2MB (no FS), 133 MHz, Small (-Os) (standard), Disabled, Disabled, Disabled, Disabled, None, Adafruit TinyUSB, IPv4 Only, Default (UF2)"

Linking everything together...
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-python3/1.0.1-base-3a57aed/python3 -I /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/tools/simplesub.py --input /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/memmap_default.ld --out /tmp/arduino_build_72866/memmap_default.ld --sub __FLASH_LENGTH__ 2093056 --sub __EEPROM_START__ 270528512 --sub __FS_START__ 270528512 --sub __FS_END__ 270528512 --sub __RAM_LENGTH__ 256k
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-gcc/2.2.0-d04e724/bin/arm-none-eabi-gcc -Werror=return-type -Wno-psabi -DUSE_TINYUSB -I/home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/Adafruit_TinyUSB_Arduino/src/arduino -DCFG_TUSB_MCU=OPT_MCU_RP2040 -DUSBD_PID=0x1029 -DUSBD_VID=0x2e8a -DUSBD_MAX_POWER_MA=250 "-DUSB_MANUFACTURER=\"WIZnet\"" "-DUSB_PRODUCT=\"W5500-EVB-Pico\"" -DPICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1 -DCYW43_LWIP=1 -DLWIP_IPV6=0 -DLWIP_IPV4=1 -DLWIP_IGMP=1 -DLWIP_CHECKSUM_CTRL_PER_NETIF=1 "-DARDUINO_VARIANT=\"wiznet_5500_evb_pico\"" -DTARGET_RP2040 -DPICO_FLASH_SIZE_BYTES=2097152 -march=armv6-m -mcpu=cortex-m0plus -mthumb -ffunction-sections -fdata-sections -fno-exceptions -DARM_MATH_CM0_FAMILY -DARM_MATH_CM0_PLUS -Os -u _printf_float -u _scanf_float -c /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/boot2/boot2_w25q080_2_padded_checksum.S -I/home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/pico-sdk/src/rp2040/hardware_regs/include/ -I/home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/pico-sdk/src/common/pico_binary_info/include -o /tmp/arduino_build_72866/boot2.o
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-gcc/2.2.0-d04e724/bin/arm-none-eabi-g++ -L/tmp/arduino_build_72866 -Werror=return-type -Wno-psabi -DUSE_TINYUSB -I/home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/Adafruit_TinyUSB_Arduino/src/arduino -DCFG_TUSB_MCU=OPT_MCU_RP2040 -DUSBD_PID=0x1029 -DUSBD_VID=0x2e8a -DUSBD_MAX_POWER_MA=250 "-DUSB_MANUFACTURER=\"WIZnet\"" "-DUSB_PRODUCT=\"W5500-EVB-Pico\"" -DPICO_CYW43_ARCH_THREADSAFE_BACKGROUND=1 -DCYW43_LWIP=1 -DLWIP_IPV6=0 -DLWIP_IPV4=1 -DLWIP_IGMP=1 -DLWIP_CHECKSUM_CTRL_PER_NETIF=1 "-DARDUINO_VARIANT=\"wiznet_5500_evb_pico\"" -DTARGET_RP2040 -DPICO_FLASH_SIZE_BYTES=2097152 -march=armv6-m -mcpu=cortex-m0plus -mthumb -ffunction-sections -fdata-sections -fno-exceptions -DARM_MATH_CM0_FAMILY -DARM_MATH_CM0_PLUS -Os -u _printf_float -u _scanf_float @/home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/platform_wrap.txt -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--script=/tmp/arduino_build_72866/memmap_default.ld -Wl,-Map,/tmp/arduino_build_72866/multicoreTest.ino.map -o /tmp/arduino_build_72866/multicoreTest.ino.elf -Wl,--no-warn-rwx-segments -Wl,--start-group /tmp/arduino_build_72866/sketch/multicoreTest.ino.cpp.o /tmp/arduino_build_72866/core/core.a /tmp/arduino_build_72866/boot2.o /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/ota.o /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/libpico.a /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/libpicow-noipv6-nobtc-noble.a /home/bobpi/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/lib/libbearssl.a -lm -lc -lstdc++ -lc -Wl,--end-group
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-gcc/2.2.0-d04e724/bin/../lib/gcc/arm-none-eabi/12.3.0/../../../../arm-none-eabi/bin/ld: /tmp/arduino_build_72866/sketch/multicoreTest.ino.cpp.o: in function `setup':
/home/bobpi/Arduino/sketch/Pico_Wiznet/multicoreTest/multicoreTest.ino:22: undefined reference to `_ZN17Adafruit_USBD_CDC5beginEm'
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-gcc/2.2.0-d04e724/bin/../lib/gcc/arm-none-eabi/12.3.0/../../../../arm-none-eabi/bin/ld: /home/bobpi/Arduino/sketch/Pico_Wiznet/multicoreTest/multicoreTest.ino:24: undefined reference to `Serial'
/home/bobpi/.arduino15/packages/rp2040/tools/pqt-gcc/2.2.0-d04e724/bin/../lib/gcc/arm-none-eabi/12.3.0/../../../../arm-none-eabi/bin/ld: /tmp/arduino_build_72866/sketch/multicoreTest.ino.cpp.o: in function `loop':
/home/bobpi/Arduino/sketch/Pico_Wiznet/multicoreTest/multicoreTest.ino:29: undefined reference to `Serial'
collect2: error: ld returned 1 exit status
exit status 1
Error compiling for board WIZnet W5500-EVB-Pico.

However this compiles ok with the Tiny USB stack

/*
 * 24MAY2024  Teest Real Time Clock DS2331
 * 
 * Tested on Wiznet5500 Pico
 * Works ok, but need a battery to full test!!
 * 
 * Tried the PICO time library but issues
 * So try with Arduino time library.
 * 
 * OK this works.  Sets the timelib from the RTC in setup and 
 * uses the Timelib to print the tiem.
 * As I use the Timelib in the heating controller this can just 
 * used with the heating controller code without much change.
 * Stll waiting for batteries to check the actual RTC is working!!
 */


//Arduino / PRJ timelib
#include <TimeLib.h>



// Date and time functions using a DS3231 RTC connected via I2C and Wire lib
#include "RTClib.h"

RTC_DS3231 rtc;

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup () {
  Serial.begin(57600);

#ifndef ESP8266
  while (!Serial); // wait for serial port to connect. Needed for native USB
#endif

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    while (1) delay(10);
  }

  if (rtc.lostPower()) {
    Serial.println("RTC lost power, let's set the time!");
    // When time needs to be set on a new device, or after a power loss, the
    // following line sets the RTC to the date & time this sketch was compiled
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
  }

  // When time needs to be re-set on a previously configured device, the
  // following line sets the RTC to the date & time this sketch was compiled
  // rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  // This line sets the RTC with an explicit date & time, for example to set
  // January 21, 2014 at 3am you would call:
  // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
   DateTime now = rtc.now();
   setTime(now.hour(), now.minute(), now.second(), now.day(), now.month(), now.year());
}

void loop () {
    DateTime now = rtc.now();

    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    Serial.print(now.day(), DEC);
    Serial.print(" (");
    Serial.print(daysOfTheWeek[now.dayOfTheWeek()]);
    Serial.print(") ");
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();

    Serial.print(" since midnight 1/1/1970 = ");
    Serial.print(now.unixtime());
    Serial.print("s = ");
    Serial.print(now.unixtime() / 86400L);
    Serial.println("d");

    // calculate a date which is 7 days, 12 hours, 30 minutes, 6 seconds into the future
    DateTime future (now + TimeSpan(7,12,30,6));

    Serial.print(" now + 7d + 12h + 30m + 6s: ");
    Serial.print(future.year(), DEC);
    Serial.print('/');
    Serial.print(future.month(), DEC);
    Serial.print('/');
    Serial.print(future.day(), DEC);
    Serial.print(' ');
    Serial.print(future.hour(), DEC);
    Serial.print(':');
    Serial.print(future.minute(), DEC);
    Serial.print(':');
    Serial.print(future.second(), DEC);
    Serial.println();

    Serial.print("Temperature: ");
    Serial.print(rtc.getTemperature());
    Serial.println(" C");

    Serial.println();
    Serial.println("Time to Arduino / PRJ Time library");
    digitalClockDisplay();  
    Serial.println("**************************************************");
    delay(3000);
}

void digitalClockDisplay(){
  // digital clock display of the time
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(year()); 
  Serial.println(); 
}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
}

[earlephilhower]

You probably still have TinyUSB selected in the menus. Use Tools->USB Stack->Pico SDK and rebuild.

[Macrosii]

Sorry , being dim here. Yes is compiles OK with PICO SDK. Why should in not compile with TinyUSB and why does the second examples compile fine with TinyUSB ?

[Macrosii]

Many Apologies
I just read the docs about the additional include with the TinyUSB stack.
What is strange though is the second set of code compiles without this! With TinyUSB selected.