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Diffstat (limited to 'compiler/GHC/Rename/Names.hs')
| -rw-r--r-- | compiler/GHC/Rename/Names.hs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/compiler/GHC/Rename/Names.hs b/compiler/GHC/Rename/Names.hs index e46d803287..aae3fe497b 100644 --- a/compiler/GHC/Rename/Names.hs +++ b/compiler/GHC/Rename/Names.hs @@ -1855,7 +1855,10 @@ mkImportMap gres RealSrcLoc decl_loc _ -> Map.insertWith add decl_loc [gre] imp_map UnhelpfulLoc _ -> imp_map where - best_imp_spec = bestImport (bagToList imp_specs) + best_imp_spec = + case bagToList imp_specs of + [] -> pprPanic "mkImportMap: GRE with no ImportSpecs" (ppr gre) + is:iss -> bestImport (is NE.:| iss) add _ gres = gre : gres warnUnusedImport :: WarningFlag -> GlobalRdrEnv |