watchexec was borne out of a few frustrations with entr, mostly around how it handles new files being created. However, from a pure design standpoint, entr is just better than most anything out there due how closely it hews to UNIX philosophy, and it gets so far on just that.
The only real improvement that can be made to these tools (currently) would be to have perfect information about what caused a file to change. Currently, most tools require you to tell it files/patterns to ignore to avoid triggering loops where the file watcher changes files and ends up triggering itself over and over. watchexec did good work here by ingesting your .gitignore and using that.
Unfortunately OSes don't provide great info when it comes to file modifications. On Linux, ptrace/LD_PRELOAD would enable us to know the set of all files changed as a result of running the file watcher (and thus ignoring them automatically). DYLD_INSERT_LIBRARIES is a thing on macOS, though it is subject to SIP restrictions with some binaries. I'm unsure what mechanism exists on Windows. The highly platform-dependent nature of this is one reason why I haven't really pursued this line of work in watchexec.
watchexec was borne out of a few frustrations with entr, mostly around how it handles new files being created. However, from a pure design standpoint, entr is just better than most anything out there due how closely it hews to UNIX philosophy, and it gets so far on just that.
The only real improvement that can be made to these tools (currently) would be to have perfect information about what caused a file to change. Currently, most tools require you to tell it files/patterns to ignore to avoid triggering loops where the file watcher changes files and ends up triggering itself over and over. watchexec did good work here by ingesting your .gitignore and using that.
Unfortunately OSes don't provide great info when it comes to file modifications. On Linux, ptrace/LD_PRELOAD would enable us to know the set of all files changed as a result of running the file watcher (and thus ignoring them automatically). DYLD_INSERT_LIBRARIES is a thing on macOS, though it is subject to SIP restrictions with some binaries. I'm unsure what mechanism exists on Windows. The highly platform-dependent nature of this is one reason why I haven't really pursued this line of work in watchexec.