vcpkg ignores default-features: false

[Thomas1664]

Describe the bug

It seems like vcpkg does not respect default-features: false in transitive dependencies. Consequently, vcpkg installs unwanted features.

Environment

• OS: Windows 10
• Compiler: not relevant
• vcpkg version: 2023-04-07-bedcba5172f5e4b91caac660ab7afe92c27a9895
• vcpkg ports commit: 6a3dd08

To Reproduce

Steps to reproduce the behavior:

1. ./vcpkg depend-info glib

• Only pcre2 depends on bzip2.
• Although pcre2 has disabled default features for bzip2, the feature tool is still selected.

Expected behavior
To not select bzip2[tool].

Failure logs

vcpkg-cmake: 
vcpkg-cmake-config:
bzip2[tool]: vcpkg-cmake, vcpkg-cmake-config
libiconv:
zlib: vcpkg-cmake
dirent:
gettext: libiconv
libffi: vcpkg-cmake, vcpkg-cmake-config
pcre2: bzip2, vcpkg-cmake, vcpkg-cmake-config, zlib
vcpkg-tool-meson:
glib: dirent, gettext, libffi, libiconv, pcre2, vcpkg-tool-meson, zlib

[autoantwort]

Duplicate of #31230

[Thomas1664]

Duplicate of #31230

Didn't find it because it was only category:question. But this is a bug, right? If I'd have to specify in my manifest that I don't want the default features of a transitive dependency, default-features: false doesn't make any sense.

[autoantwort]

But this is a bug, right?

No this is by design.

If I'd have to specify in my manifest that I don't want the default features of a transitive dependency, default-features: false doesn't make any sense.

It still makes sense. Otherwise would be not able to disable the tool feature of bzip2 at all. So by default "xyz" in a manifest means xyz[defaults] and with default-features: false it means xyz[core] so default features can be disabled by the top level/users manifest.

[Thomas1664]

Let me clarify: It doesn't make sense to put default-features: false in a port in the catalogue if default features are selected anyway.

[autoantwort]

It still makes sense. Otherwise would be not able to disable the tool feature of bzip2 at all. So by default "xyz" in a manifest means xyz[defaults] and with default-features: false it means xyz[core] so default features can be disabled by the top level/users manifest.

Example:
Port B exits with a default feature def.
Port A depends on B.
You install A and B[core] => You get A[core] and B[core,def]

Now you use default-features: false in a port in the catalogue (in this example B)
Port B exits with a default feature def.
Port A depends on B[core].
You install A and B[core] => You get A[core] and B[core]

[Thomas1664]

I don't think it has to do with transitive dependencies. Lets use real ports. In my example, I tried to install glib. glib depends on pcre2. pcre2 depends on bzip2 and uses default-features: false to get rid of bzip2[tool]. Even if I install pcre2, I get bzip2[tool].

This is the output of vcpkg depend-info pcre2:

vcpkg-cmake: 
vcpkg-cmake-config:
bzip2[tool]: vcpkg-cmake, vcpkg-cmake-config
zlib: vcpkg-cmake
pcre2: bzip2, vcpkg-cmake, vcpkg-cmake-config, zlib

Now I remove default-features: false in pcre2 for the bzip2 dependency. The output of vcpkg depend-info pcre2 stays the same. But when I try vcpkg install pcre2 bzip2[core] it still includes the tool feature. This doesn't happen anymore if I'd restore default-features: false.

I understand the need for default-features: false now. However, this does not explain why vcpkg install pcre2 has to include bzip2[tool]. If one port disables a default feature and no other port needs that feature, what is the point of ignoring the fact that the feature was explicitly disabled?

[autoantwort]

If one port disables a default feature and no other port needs that feature, what is the point of ignoring the fact that the feature was explicitly disabled?

You can follow one of the many discussions about that here: #26664 (comment)
It is a design decision that was done in the past. I don't want to discuss it again.