legacy-support headers should work with later SDK versions

[fhgwright (Fred Wright)]

It's ordinarily legal (with some limitations) to build for a given OS target while using an SDK for a later OS version. In some cases, the legacy-support headers may not work properly in this situation. One known case is #69838.

It would be desirable (though not high priority) to fix this.

[fhgwright (Fred Wright)]

In df195e0aea5b49d03c149970ddb303bcada0f7d7/macports-legacy-support (master):

stpncpy: Fix potential header collision with "later" SDK

This is one case of the general problem in:

#69867

This should fix the only known case specifically related to collisions
with "secure" wrappers. Whether there are other types of SDK
collisions is TBD.

TESTED:
Builds and passes tests on 10.4-10.5 ppc, 10.4-10.6 i386, 10.5-10.6
ppc (i386 Rosetta), 10.5-12.x x86_64, 11.x-14.x arm64.
Builds test_stpncpy successfully on 10.6 with 10.7 SDK.

[Christopher Nielsen <mascguy@…>]

In badcd63f0127ac3034d9522fb7445f9a873f899b/macports-ports (master):

legacy-support-devel: update to latest master

• stpncpy: Fix potential header collision with "later" SDK

See: ​https://github.com/macports/macports-legacy-support/pull/85
See: #69867

[fhgwright (Fred Wright)]

One thing that would help in testing this issue would be to teach the build procedure to honor SDKROOT. Currently it doesn't.

[ryandesign (Ryan Carsten Schmidt)]

The build procedure of what? If you mean you are setting the SDKROOT environment variable in your shell and MacPorts is not passing it through to the builds, that's intentional; most environment variables are deliberately not passed through. You can override configure.sdk_version or configure.sdkroot on the command line if you want to test a different SDK, e.g. sudo port configure configure.sdk_version=11 (this assumes you have the macOS 11 SDK in the standard location) or sudo port configure configure.sdkroot=/path/to/MacOSX11.sdk (for an SDK located anywhre).

[fhgwright (Fred Wright)]

Replying to ryandesign:

The build procedure of what? If you mean you are setting the SDKROOT environment variable in your shell and MacPorts is not passing it through to the builds, that's intentional; most environment variables are deliberately not passed through. You can override configure.sdk_version or configure.sdkroot on the command line if you want to test a different SDK, e.g. sudo port configure configure.sdk_version=11 (this assumes you have the macOS 11 SDK in the standard location) or sudo port configure configure.sdkroot=/path/to/MacOSX11.sdk (for an SDK located anywhre).

No, I mean the project's build procedure. Testing it as a port would add unnecessary friction.

An example of why legacy-support should have its own ticket component, since this isn't a ports issue. :-)