macOS: The ETA in f3write 10.0 is incorrect.

[Chamiu]

Since updating to f3 10.0, running f3write on a 16GB micro SD plugged into an SD card reader via a USB hub throws up a ridiculous ETA like the one below.

f3write /Volumes/Big\ Download 
F3 write 10.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Free space: 14.25 GB
Creating file 1.h2w ... 0.01% -- 52.31 KB/s -- 3 weeks 2 days 2:21:43

When I rolled back to f3 9.0, it showed this ETA instead.

f3write /Volumes/Big\ Download 
F3 write 9.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Removing old file 1.h2w ...
Free space: 14.25 GB
Creating file 1.h2w ... 0.02% -- 97.17 KB/s -- 45:52:11

Seems like a bug with the f3write ETA, at the very least. Has anyone else seen this?

Homebrew 5.1.14-189-gc6a08de
macOS Tahoe.5
MacBook Air Late 2020

---

This post was translated from Japanese to English using Kagi Translate.

[AltraMayor]

Hi @Chamiu,

Could you test pull request #278? I think it addresses the problem you're experiencing.

[mgarciaisaia]

I've just tested this PR, but I can't reproduce the original issue to start with - this PR seems to work exactly as right as v10.0 to me.

This is my running the commit right before this PR:

$ uname -a
Darwin ARMita.local 24.6.0 Darwin Kernel Version 24.6.0: Tue Apr 21 20:19:01 PDT 2026; root:xnu-11417.140.69.710.16~1/RELEASE_ARM64_T6000 arm64
$ git rev-parse HEAD
3ec5ee904adc12e477481ee9027bedf52da618e8
$ make clean
rm -rf build cscope.out
$ make
mkdir -p build
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libutils.c -o build/libutils.o
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libfile.c -o build/libfile.o
src/libfile.c:221:29: warning: no newline at end of file [-Wnewline-eof]
  221 | #endif  /* Apple Macintosh */
      |                              ^
1 warning generated.
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libflow.c -o build/libflow.o
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/f3write.c -o build/f3write.o
cc -o build/f3write build/libutils.o build/libfile.o build/libflow.o build/f3write.o -L/opt/homebrew/lib -largp -lm
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/f3read.c -o build/f3read.o
cc -o build/f3read build/libutils.o build/libfile.o build/libflow.o build/f3read.o -L/opt/homebrew/lib -largp -lm
$ build/f3write /Volumes/NO\ NAME/
F3 write 10.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Free space: 119.03 GB
Creating file 1.h2w ... 0.21% -- 45.26 MB/s -- 45'57"^C

I get the same ETA for 67b8a5d (tag v10.0), and for f07f64f (this PR).

[mgarciaisaia]

FYI: this PR adds one extra warning during compilation:

$ git rev-parse HEAD
f07f64f16aee4c5fcc8bbca2b5c2d39b71de6e84
$ make clean
rm -rf build cscope.out
$ make
mkdir -p build
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libutils.c -o build/libutils.o
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libfile.c -o build/libfile.o
In file included from src/libfile.c:42:
src/libutils.h:32:9: warning: 'MIN' macro redefined [-Wmacro-redefined]
   32 | #define MIN(a, b) _Generic(1 ? (a) : (b),       \
      |         ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/param.h:215:9: note: previous definition is here
  215 | #define MIN(a, b) (((a)<(b))?(a):(b))
      |         ^
src/libfile.c:261:29: warning: no newline at end of file [-Wnewline-eof]
  261 | #endif  /* Apple Macintosh */
      |                              ^
2 warnings generated.
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/libflow.c -o build/libflow.o
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/f3write.c -o build/f3write.o
cc -o build/f3write build/libutils.o build/libfile.o build/libflow.o build/f3write.o -L/opt/homebrew/lib -largp -lm
cc -std=c17 -Wall -Wextra -pedantic -MMD -ggdb -I/opt/homebrew/include -c src/f3read.c -o build/f3read.o
cc -o build/f3read build/libutils.o build/libfile.o build/libflow.o build/f3read.o -L/opt/homebrew/lib -largp -lm
$ build/f3write /Volumes/NO\ NAME/
F3 write 10.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Removing old file 1.h2w ...
Free space: 118.76 GB
Creating file 1.h2w ... 0.27% -- 37.36 MB/s -- 51'55"^C

[AltraMayor]

Thank you very much for testing the pull request, @mgarciaisaia.

I'll wait for more information from @Chamiu or other users to further narrow this issue.