fmtlib/fmt

`export(` should not be scoped by `FMT_INSTALL`

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#4,806 opened on Jun 14, 2026

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help wanted

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Description

Currently the export(...) cmake directive is scoped inside if (FMT_INSTALL): https://github.com/fmtlib/fmt/blob/11ddbcb7898d2d3445d431a54814367b21dee6ad/CMakeLists.txt#L496-L499

However, there are cases in which downstream projects might not want to install fmt but might still want to provide a export(...) themselves. However, this is impossible to do when depending on another target that doesn't export itself. CMake will error with something like

CMake Error: export("MyLibTargets" ...) includes target "mylib" which requires target "fmt" that is not in any export set.

Since having the exported target files in the build tree don't harm anyone, I suggest just unconditionally exporting regardless of whether FMT_INSTALL is true or not.

See also e.g. https://github.com/Kistler-Group/sdbus-cpp/pull/523

Contributor guide

Research direction
Move the `export(...)` directive outside the `if (FMT INSTALL)` block in CMakeLists.txt to allow downstream projects to export targets even when FMT INSTALL is off.
Tech stack
cpp
Domain
build system
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
CMake
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70