# Why this Clojure "var" error?
**URL:** https://clojureverse.org/t/why-this-clojure-var-error/6425
**Category:** Troubleshooting
**Tags:** clojure
**Created:** [August 21, 2020, 8:21pm UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425 "2020-08-21T20:21:37Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Webdev\_Tory](https://clojureverse.org/u/Webdev_Tory)
#### Post date: [August 21, 2020, 8:21pm UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425/1 "2020-08-21T20:21:37Z")
We were attempting to write functions could round-trip function references to strings and, though we eventually figured this out in a different way, our first attempts brought a very confusing error. It seems to have something to do with how `var` works, and some underlying characteristic of Clojure that I would love to understand.
We were adapting [this macro](https://stackoverflow.com/questions/22116257/how-to-get-functions-name-as-string-in-clojure), which worked in the REPL: `(defmacro fn-name [f] `(-> ~f var meta :name str))` . But it failed when written as a larger fn, below, and even with `macro-expand1` it wasn’t clear what was going wrong, although trial and error indicated that it has something do with with how `var` works. Can anyone shed some light on the nature of the problem?
```clojure
(defn foo [] nil)
(defmacro parse-fn->string_fails
"Should parse a function, like `clojure.core/str`, to a string \"clojure.core/str\" "
[f]
`(let [m (-> ~f var meta)
fname (:name m)
fns (:ns m)]
(str fns "/" fname)))
(parse-fn->string_fails foo)
;; =>
;; Call to clojure.core/let did not conform to spec.
;; #:clojure.spec.alpha{:problems ({:path [:bindings :form :local-symbol], :pred clojure.core/simple-symbol?, :val logging.core/m, :via [:clojure.core.specs.alpha/bindings :clojure.core.specs.alpha/bindings ...
```
---
### Author:  [@seancorfield](https://clojureverse.org/u/seancorfield)
#### Post date: [August 21, 2020, 8:47pm UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425/2 "2020-08-21T20:47:32Z")
Local symbols in macros must be gensym’d, i.e., `m#`, `fname#`, `fns#`.
---
### Author:  [@joinr](https://clojureverse.org/u/joinr)
#### Post date: [August 21, 2020, 9:30pm UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425/3 "2020-08-21T21:30:45Z")
Per sean’s response:
```
user>(pprint (macroexpand-1 '(parse-fn->string_fails foo)))
(clojure.core/let
[user/m
(clojure.core/-> foo var clojure.core/meta)
user/fname
(:name user/m)
user/fns
(:ns user/m)]
(clojure.core/str userfns "/" user/fname))
(defmacro parse-fn->string_fails
"Should parse a function, like `clojure.core/str`, to a string \"clojure.core/str\" "
[f]
`(let [m# (-> ~f var meta)
fname# (:name m#)
fns# (:ns m#)]
(str fns# "/" fname#)))
```
now yields:
```
(clojure.core/let
[m __16497__ auto__
(clojure.core/-> foo var clojure.core/meta)
fname __16498__ auto__
(:name m __16497__ auto__)
fns __16499__ auto__
(:ns m __16497__ auto__)]
(clojure.core/str fns __16499__ auto __"/" fname__ 16498 __auto__ ))
```
Which works. In the `fn-name` macro, you didn’t have this problem since you didn’t have a let binding with symbols. In the new macro, without gensyms, the unquoted symbols in the let were expanded into ns-qualified symbols, which were unable to resolve and triggered errors during evaluation of the `let` form. With the gensyms generating valid unqualified symbols for `let`, you now have valid bindings and the macro works.
---
### Author:  [@Webdev\_Tory](https://clojureverse.org/u/Webdev_Tory)
#### Post date: [August 21, 2020, 9:55pm UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425/4 "2020-08-21T21:55:23Z")
Ah! That makes perfect sense! Thank you!
---
### Author:  [@system](https://clojureverse.org/u/system)
#### Post date: [February 20, 2021, 9:55am UTC](https://clojureverse.org/t/why-this-clojure-var-error/6425/5 "2021-02-20T09:55:23Z")
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