Conda Forge recently converted to exclusively emitting .conda files for its package builds, instead of .tar.gz files. With the tarballs, we could previously use tar to unpack the archive.
How can one unpack the .conda archive files?
Naively trying gzip gives
$ gzip -d libtiff-4.5.0-h82bc61c_0.conda
gzip: libtiff-4.5.0-h82bc61c_0.conda: unknown suffix -- ignored
and forcing the suffix with -S .conda reports
$ gzip -d -S .conda libtiff-4.5.0-h82bc61c_0.conda
gzip: libtiff-4.5.0-h82bc61c_0.conda: not in gzip format
The blog post introducing the format mentions zstandard compression format, but using zstd doesn't seem to fare any better:
$ zstd -d libtiff-4.5.0-h82bc61c_0.conda
zstd: libtiff-4.5.0-h82bc61c_0.conda: unknown suffix (.zst/.tzst expected). Can't derive the output file name. Specify it with -o dstFileName. Ignoring.
$ zstd -d -o libtiff libtiff-4.5.0-h82bc61c_0.conda
zstd: libtiff-4.5.0-h82bc61c_0.conda: unsupported format
Conda provides a Python package, conda-package-handling (see documentation), which comes installed with the base environment. This includes a CLI entry point, cph, for working with Conda packages. One can extract a .conda archive using, for example,
$ cph extract libtiff-4.5.0-h82bc61c_0.conda
For reference, here is the help message the tool emits:
$ cph -h
usage: cph [-h] [-V] {extract,x,create,c,verify,v,transmute,t} ...
optional arguments:
-h, --help show this help message and exit
-V, --version Show the conda-package-handling version number and exit.
subcommands:
{extract,x,create,c,verify,v,transmute,t}
extract (x) extract package contents
create (c) bundle files into a package
verify (v) verify converted files against their reference
transmute (t) convert from one package type to another