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linuxhaskelllinkerglibcstatic-linking

Finding haskell executable if statically linked via glibc or musl

I have an executable build via ghc which I know is statically compiled. I want to find if it's statically linked via glibc or musl based (Mostly because glibc based static linking is discouraged: Why is statically linking glibc discouraged? )

I would be also interested in an answer to see if there a non Haskell based solution which is applicable to any executable (basically executable which doesn't ship with Haskell's RTS).

Solution

  • One way of finding it, although it's limited to haskell based executable is using the --info option:

    Example:

    $ ./tldr +RTS --info -RTS
 [("GHC RTS", "YES")
 ,("GHC version", "8.6.5")
 ,("RTS way", "rts_thr")
 ,("Build platform", "x86_64-alpine-linux")
 ,("Build architecture", "x86_64")
 ,("Build OS", "linux")
 ,("Build vendor", "alpine")
 ,("Host platform", "x86_64-alpine-linux")
 ,("Host architecture", "x86_64")
 ,("Host OS", "linux")
 ,("Host vendor", "alpine")
 ,("Target platform", "x86_64-alpine-linux")
 ,("Target architecture", "x86_64")
 ,("Target OS", "linux")
 ,("Target vendor", "alpine")
 ,("Word size", "64")
 ,("Compiler unregisterised", "NO")
 ,("Tables next to code", "YES")
 ]

    From the x86_64-apline-linux, I can confirm that the build was based on Alpine Linux which is based on musl. You can explicitly confirm via ldd that it is indeed statically linked then:

    $ ldd ./tldr
        not a dynamic executable