# Incompatible pointer type error in fluid.plotter.c when compiling puredata external for Raspberry Pi

**URL:** https://discourse.flucoma.org/t/incompatible-pointer-type-error-in-fluid-plotter-c-when-compiling-puredata-external-for-raspberry-pi/2693
**Category:** Bug Reports and Issues
**Created:** [November 30, 2025, 12:04pm UTC](https://discourse.flucoma.org/t/incompatible-pointer-type-error-in-fluid-plotter-c-when-compiling-puredata-external-for-raspberry-pi/2693 "2025-11-30T12:04:29Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![enrique\_t](https://discourse.flucoma.org/letter_avatar_proxy/v4/letter/e/439d5e/32.png) [@enrique\_t](https://discourse.flucoma.org/u/enrique_t)
#### Post date: [November 30, 2025, 12:04pm UTC](https://discourse.flucoma.org/t/incompatible-pointer-type-error-in-fluid-plotter-c-when-compiling-puredata-external-for-raspberry-pi/2693/1 "2025-11-30T12:04:30Z")

</div>

Hi,

compiling flucoma-pd external for raspberry pi (Raspian Debian 13.2) results in an incompatible pointer error:

fluid.plotter.c:715:74: error: assignment to ´t\_fpoint \*´ {aka ´struct \_fpoint \*´} from incompatible pointer type ´t\_symbol \*´{aka ´stru t \_symbol \*´} [-Wincompatible-pointer-types] x-\>x\_send = x-\>x\_snd\_raw = x-\>x\_receive = x-\>x\_rcv\_raw = x-\>x\_points = &s\_;

I think **`x_send`** , **`x_snd_raw`** , **`x_receive`** , **`x_rcv_raw`** are all **`t_symbol *`**

- **`x_points`** is **`t_fpoint *`**

- **`&s_`** is a **`t_symbol *`** \*\_

So assigning **`&s_`** to **`x_points`** is invalid and the compiler correctly complains.

I changed the initialization in fplot\_new so that the symbol fields are still initialised to **`&s_`** and **`x_points`** is initialised separately as a **`t_fpoint *`** , using **`NULL`** \*\_ The changes are around lines 715-717:

`x->x_edit = cv->gl_edit;`  
`x->x_send = x->x_snd_raw = x->x_receive = x->x_rcv_raw = &s_;`  
`x->x_points = NULL;`  
`x->x_rcv_set = x->x_snd_set = x->x_latch = x->x_nbhighlight = x->x_x_min = x->x_y_min = x->x_x_refmin = x->x_y_refmin = 0;`

With this it now compiles and the external seems to run ok.

---

<div class="post-metadata">

### Author: ![tremblap](https://discourse.flucoma.org/user_avatar/discourse.flucoma.org/tremblap/32/5_2.png) [@tremblap](https://discourse.flucoma.org/u/tremblap)
#### Post date: [December 1, 2025, 11:22am UTC](https://discourse.flucoma.org/t/incompatible-pointer-type-error-in-fluid-plotter-c-when-compiling-puredata-external-for-raspberry-pi/2693/2 "2025-12-01T11:22:17Z")

</div>

hello!

Thanks for this, I’ll check a bit more when I’m out of this week’s double rush, to make sure it was a real error from my side and also that I can correct waveform (which is almost the same code so should have that error too)

more soon

---

<div class="post-metadata">

### Author: ![tremblap](https://discourse.flucoma.org/user_avatar/discourse.flucoma.org/tremblap/32/5_2.png) [@tremblap](https://discourse.flucoma.org/u/tremblap)
#### Post date: [July 28, 2026, 1:18pm UTC](https://discourse.flucoma.org/t/incompatible-pointer-type-error-in-fluid-plotter-c-when-compiling-puredata-external-for-raspberry-pi/2693/3 "2026-07-28T13:18:13Z")

</div>

ok that variable is a leftover so I deleted it altogether. The nightlies are updated and the tip of main should compile as-is

thanks!