error right off the bat about sdfat-particle HOT 1 OPEN

This version of SdFat has not been supported for a long time and has no directory SdFat/SdCard.

You should use SdFat-beta since it has several fixes for Particle boards.

The current version of SdFat-beta has definitions using F_CPU but symbols using F_CPU should not be used for Particle boards.

I tested SdFat-beta with a Particle Argon board before the last release of SdFat-beta.

Do not use the following symbols for SPI speed. They are for compatibility with old versions of SdFat. I will redefine them without F_CPU in the next release of SdFat-beta. They date back to AVR boards and Arduino Due.

#define SPI_DIV3_SPEED SD_SCK_HZ(F_CPU/3)
/** Set SCK rate to F_CPU/4. */
#define SPI_HALF_SPEED SD_SCK_HZ(F_CPU/4)
/** Set SCK rate to F_CPU/6 for Due */
#define SPI_DIV6_SPEED SD_SCK_HZ(F_CPU/6)
/** Set SCK rate to F_CPU/8. */
#define SPI_QUARTER_SPEED SD_SCK_HZ(F_CPU/8)
/** Set SCK rate to F_CPU/16. */
#define SPI_EIGHTH_SPEED SD_SCK_HZ(F_CPU/16)
/** Set SCK rate to F_CPU/32. */
#define SPI_SIXTEENTH_SPEED SD_SCK_HZ(F_CPU/32)

from sdfat-particle.